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  • 151.
    Klass, Verena
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Giordano, Giuseppe
    Chalmers University of Technology, Sweden.
    Behm, Mårten
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Sjöberg, Jonas
    Chalmers University of Technology, Sweden.
    Dynamical Lithium-Ion Battery Model Identificationusing Electric Vehicle Operating Data for Resistance EstimationManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    State-of-health (SOH) estimates of batteries are essential on-board electric vehicles (EVs) in order to provide safe, reliable, and cost-effective battery operation. Here, we present an approach for the estimation of the battery SOH indicator internal resistance. Battery models are constructed on the basis of ordinary EV operating data. The 10 s discharge resistance, which is an established battery figure-of-merit from laboratory testing, can be conveniently computed from the identified model parameters. Dynamical battery models based on a current input and a voltage output with model parameters dependent on temperature and state-of-charge (SOC) are derived using AutoRegressive with eXogenous input (ARX) models. The suggested method is validated with usage data from emulated EV operation of an automotive lithium-ion battery cell. The resistance values are estimated accurately by the proposed model for a SOC and temperature range spanning typical EV operating conditions (average relative estimation error of 1.5%). The method even provides an uncertainty interval for the resistance estimations, which is found to be very narrow. The linear identification of the model parameters and the resistance computation are very fast rendering the method suitable for on-board application.

  • 152.
    Klass, Verena
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Svens, Pontus
    Scania CV AB.
    Behm, Mårten
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    State-of-health estimation of lithium-ion battery under emulated HEV operation on board heavy-duty truckManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    This paper addresses the need for simple and cost-effective methods that detect the state-of-health (SOH) of batteries in vehicle applications solely based on data readily available from the battery management system without any knowledge of battery properties, prior laboratory measurements or additional equipment.

    A power-optimized lithium-ion battery cell is operated in an emulated hybrid electric vehicle (HEV) environment on board a conventional heavy-duty truck. The HEV operation of the battery cell depends on the driving pattern of the truck within set limits. Beyond the HEV operation, the performance of the battery cell is periodically measured with on-board standard pulse and capacity tests. On basis of the battery operating data collected in the field test, support vector machine-based battery models are built. From a model input of current, temperature, state-of-charge, and current history, the model accurately estimates the battery voltage despite the tough HEV operating conditions with high current pulses. This data-driven battery model is used to estimate the battery cell’s charge and discharge resistance as well as capacity, i.e. the performance measures verified with the standard tests. These SOH indicators can be predicted by the model with adequate accuracy for on-board SOH detection and are followed throughout the one-year field test period.

  • 153.
    Klemedsson, Shicarra
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Flocculation of natural organic matter in Swedish lakes2012Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Flocculation is an important part of the carbon cycle. It is therefore crucial to understand how flocculation is regulated and how different environmental factors impact. A dilemma is that it has been found difficult to measure flocculation experimentally.

    In this thesis, flocculation of dissolved organic carbon in a Swedish lake was measured in a series of laboratory experiments. The method used was Dynamic Light Scattering (DLS). DLS is used to determine the size distribution profile of, for instance, small particles in suspension. DLS measures Brownian motion and relates it to the particle size by measuring the fluctuation in scattering intensity. It is not very effective to measure the frequency spectrum contained in the intensity fluctuations directly, so instead, a digital auto correlator is used.

    Since factors such as pH, salinity and calcium chloride content varies in lakes and is thought to have an impact on flocculation, this was investigated as well. As pH was changed in a range of 3 to 9, small changes in size distribution could be detected. Salinity and calcium chloride content have quite an impact on flocculation. Time also has a great impact, samples that were set to rest for a week showed a significant increase in particle size.

    For DLS to work, the samples need to be filtered of centrifuged to get rid of large particles. Different types of filters were tested to see which filter material was the best to use. When filtering the water we only want to filter out the large particles. Natural organic matter has a hydrophobic component which adsorbs to some filter types but not to others. It is crucial to know which filters this hydrophobic component adsorbs to, so that the loss of dissolved organic carbon during filtration can be minimalized.

  • 154.
    Kortsdottir, Katrin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Pérez Ferriz, Francisco Javier
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lagergren, Carina
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Wreland Lindström, Rakel
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Reformate Hydrogen Fuel in PEM Fuel Cells: the Effect of Alkene Impurities on Anode Activity2013Inngår i: ECS Transactions, Electrochemical Society, 2013, s. 1857-1865Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Reformate hydrogen contains many impurities, some are well known while others have been less studied. Hydrocarbons are possible impurities in reformate hydrogen and are among those less studied. This study if aimed at alkenes, with special focus on propene. Adsorption and desorption on the Pt catalyst is studied using stripping cyclic voltammetry combined with mass spectrometry. The results show that although the effect of propene in the presence of hydrogen is expected to be minimal, adsorption and blockage of catalytic sites cannot be ruled out. A small amount of ad-species is formed on Pt at low adsorption potentials, and in the presence of hydrogen, although suppression of the hydrogen desorption peak was minimal if hydrogen was adsorbed on the Pt catalyst prior to exposure.

  • 155.
    Kortsdottir, Katrin
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Wreland Lindström, Rakel
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Dominiguez Fernandez, Carlota
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Hydrogen fuel impurities: The effect of CO2 and hydrocarbons at the anode of a PEM fuel cell2011Inngår i: Proceedings of EFC2011, 2011, s. EFC11159-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hydrogen fuel produced by reforming contains, in addition to hydrogen, CO2, CO, sulphur compounds and small hydrocarbons in varying amount. The effect of CO2 and a few example hydrocarbons has been studied on traditional PEM fuel cell anodes by cyclic voltammetry and constant load experiments. In addition, Electrochemical Impedance Spectroscopy and Mass Spectrometry have been employed to aid in the analysis. The effect of adsorption potential, cell temperature, humidity of the feed gases and concentrations of selected impurities has been studied.

  • 156.
    Krewer, Christoffer
    et al.
    RISE - Research Institutes of Sweden, Biovetenskap och material, Jordbruk och livsmedel.
    Davis, Jennifer
    RISE - Research Institutes of Sweden, Biovetenskap och material, Jordbruk och livsmedel.
    Woodhouse, Anna
    RISE - Research Institutes of Sweden, Biovetenskap och material, Jordbruk och livsmedel.
    Östergren, Karin
    RISE - Research Institutes of Sweden, Biovetenskap och material, Jordbruk och livsmedel.
    Holtz, Emma
    RISE - Research Institutes of Sweden, Biovetenskap och material, Jordbruk och livsmedel.
    Early phase design tool for non-LCA experts: Integrating environmental assessment in the development of novel processing technology in food industry2017Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The Life Cycle Assessment methodology often applies a product perspective but can be used to assess novel production technologies by comparing novel products with a baseline product, as long as the functional unit of the product is considered to be the same. There is increasing environmental concerns in society and pressures on industry to take into account their impact on the environment. Tools are available for this, but not tools adapted to specific industry needs. The reasons to use LCA are foremost to guide the development towards the most sustainable solutions and to evaluate the market potential from an environmental perspective. Challenges arise when applying LCA in early development stages, e.g. getting access to recent development data, to increase commitment and incentives to take early LCA results into consideration, to present results in an attractive way etc. LCA calculations must also keep up with the sometimes rapid development. In order to meet these challenges interactive report software have been introduced to industrial partners (non-LCA experts) in an EU project called FutureFood (Grant agreement no: 635759). The project goal is to develop a new processing technology for foods (CO2 drying). In order to meet the LCA related challenges a platform has been used that is developed by PRé Consultants (Pre, 2016?), called Share and Collect. It allows LCA experts to develop tools for non-experts so that users are able to alter parameters in the LCA model and assess the result of the changes. It is done by providing the industrial partners with an intuitive web based graphical user interface (GUI). When a user changes input data in the GUI, parameter values also change in the model, an LCA calculation engine runs the model and the GUI presents the corresponding results. In the project a tool for assessing the processing technology has been developed and the industrial partners  are provided rights to access the tools and create ‘what if’ scenarios. Examples of changes are change of electricity production, transport distances, transport types or modes, raw material source, packaging, production resource or energy efficiency etc. The tool has been evaluated by the non-LCA expert industrial partners, and the first review results show that it is user friendly, visually appealing and interesting in its interactive way because of the instant feedback of results. Tailored models such as the ones developed in the project have the potential to support knowledge based decisions in innovation projects in companies.

  • 157.
    Kuhn, Joel
    et al.
    University of Toronto, Department of Mechanical and Industrial Engineering, Toronto, Ontario M5S 3G8, Canada.
    Gupta, Mohit Kumar
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT).
    Kesler, Olivera
    University of Toronto, Department of Mechanical and Industrial Engineering, Toronto, Ontario M5S 3G8, Canada.
    Björklund, Stefan
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avdelningen för avverkande och additativa tillverkningsprocesser (AAT).
    The Effect of Fuel Electrode Roughness on the Properties of Plasma Sprayed Solid Oxide Cells2018Inngår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 165, nr 9, s. F693-F701Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solid oxide cell electrolytes fabricated by atmospheric plasma spraying are frequently found to have considerable gas leak rates.Electrode surface roughness is known to have an influence on electrolyte leak rates. A jet of high velocity air, produced with an airknife, was aimed at the plasma plume during fuel electrode deposition to reduce the surface roughness prior to electrolyte deposition.The resulting fuel electrode masses, electrode compositions, and electrode surface roughnesses were measured for varying air knifeinlet pressures. Surface asperity populations and maximum heights were significantly reduced using air knife pressures of >6 barat the expense of deposition efficiency. The nickel volume fraction in the fuel electrode increased slightly with increasing air knifepressure. Open circuit voltages were larger on the smoother fuel electrodes that were produced at higher air knife pressures, but nosignificant effect of air knife pressure on cell power density could be discerned.© 2018 The Electrochemical Society

  • 158. Kumagai, Y.
    et al.
    Barreiro Fidalgo, Alexandre
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Jonsson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Impact of Stoichiometry on the Mechanism and Kinetics of Oxidative Dissolution of UO 2 Induced by H 2 O 2 and γ-Irradiation2019Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, nr 15, s. 9919-9925Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Radiation-induced oxidative dissolution of uranium dioxide (UO 2 ) is one of the most important chemical processes of U driven by redox reactions. We have examined the effect of UO 2 stoichiometry on the oxidative dissolution of UO 2 in aqueous sodium bicarbonate solution induced by hydrogen peroxide (H 2 O 2 ) and γ-ray irradiation. By comparing the reaction kinetics of H 2 O 2 between stoichiometric UO 2.0 and hyper-stoichiometric UO 2.3 , we observed a significant difference in reaction speed and U dissolution kinetics. The stoichiometric UO 2.0 reacted with H 2 O 2 much faster than the hyper-stoichiometric UO 2.3 . The U dissolution from UO 2.0 was initially much lower than that from UO 2.3 but gradually increased as the oxidation by H 2 O 2 proceeded. Increase in the initial H 2 O 2 concentration caused decrease in the U dissolution yield with respect to the H 2 O 2 consumption both for UO 2.0 and UO 2.3 . This decrease in the U dissolution yield is attributed to the catalytic decomposition of H 2 O 2 on the surface of UO 2 . The γ-ray irradiation induced the U dissolution that is analogous to the kinetics by the exposure to a low concentration (2 × 10 -4 mol dm -3 ) of H 2 O 2 . The exposure to higher H 2 O 2 concentrations caused lower U dissolution and resulted in deviation from the U dissolution behavior by γ-ray irradiation.

  • 159.
    Kusar, Henrik
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Catalytic combustion of liquid fuel over complex metal oxides2010Konferansepaper (Fagfellevurdert)
  • 160.
    Kusar, Henrik
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    CuO-CeO2 and CuO-ZnO nanoparticles prepared from a novel oil-in-water microemulsion reaction method: their use as catalyst in water-gas shift reaction2011Konferansepaper (Fagfellevurdert)
  • 161.
    Kusar, Henrik
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Sulfur poisoning in catalytic combustion of gasified industrial waste2001Inngår i: Studies in Surface Science and Catalysis, ISSN 0167-2991, Vol. 139, s. 463-Artikkel i tidsskrift (Fagfellevurdert)
  • 162.
    Kusar, Henrik
    KTH, Tidigare Institutioner, Kemiteknik.
    The Influence of Pd: Pt Molar Ratio on Methane Combustion2004Konferansepaper (Fagfellevurdert)
  • 163.
    Kusar, Henrik
    KTH, Tidigare Institutioner, Kemiteknik.
    Water gas shift and preferential oxidation processes for low temperature fuel cell grade H2 production over the nanostructured CuxCe(1-x)O(2-y) catalyst2004Konferansepaper (Annet vitenskapelig)
  • 164. Kusar, Henrik
    Water gas shift reaction over nanostructured copper-ceria catalyst2006Konferansepaper (Fagfellevurdert)
  • 165. Kusar, Henrik
    et al.
    Dalle Nogare, D.
    Canu, P.
    Jaras, S.
    Modelling CO oxidation kinetics in an annular reactor2006Konferansepaper (Fagfellevurdert)
  • 166.
    Kusar, Henrik
    et al.
    Laboratory of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana, Slovenia.
    Hocevar, S.
    Laboratory of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana, Slovenia.
    Levec, J.
    Laboratory of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana, Slovenia.
    Kinetics of the water-gas shift reaction over nanostructured copper-ceria catalysts2006Inngår i: Applied Catalysis B: Environmental, ISSN 0926-3373, E-ISSN 1873-3883, Vol. 63, nr 3-4, s. 194-200Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Water–gas shift reaction was studied over two nanostructured CuxCe1−xO2−y catalysts: a Cu0.1Ce0.9O2−ycatalyst prepared by a sol–gel method and a Cu0.2Ce0.8O2−y catalyst prepared by co-precipitation method. A commercial low temperature water–gas shift CuO–ZnO–Al2O3 catalyst was used as reference. The kinetics was studied in a plug flow micro reactor at an atmospheric pressure in the temperature interval between 298 and 673 K at two different space velocities: 5.000 and 30.000 h−1, respectively. Experimentally estimated activation energy, Eaf, of the forward water–gas shift reaction at CO/H2O = 1/3 was 51 kJ/mol over the Cu0.1Ce0.9O2−y, 34 kJ/mol over the Cu0.2Ce0.8O2−y and 47 kJ/mol over the CuO–ZnO–Al2O3 catalyst. A simple rate expression approximating the water–gas shift process as a single reversible surface reaction was used to fit the experimental data in order to evaluate the rate constants of the forward and backward reactions and of the activation energy for the backward reaction.

  • 167.
    Kusar, Henrik
    et al.
    Laboratory of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana, Slovenia.
    Hocevar, Stanko
    Levec, Janez
    Water-Gas Shift Reaction Kinetics Over Nanostructured Copper-Ceria Catalysts2006Konferansepaper (Fagfellevurdert)
  • 168.
    L'ABBATE, MARIO ENRICO
    KTH, Skolan för kemivetenskap (CHE).
    Hydrokrackning av FT vaxer på ädelmetall / kiseloxid - aluminiumoxidkatalysatorer: en experimentell och modelleringsstudie2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Synthetic fuel production employing the Fischer-Tropsch (FT) technology will, most likely, play an important role in the future energy system. FT waxes can be upgraded to middle distillates through a hydroprocessing step that combines isomerization and cracking reactions.

    Different catalysts can be employed in the hydroconversion of FT waxes. It is usually carried out on bifunctional catalysts that possess a metal and an acidic function. The former provides the hydrogenation/dehydrogenation activity while the latter catalyzes isomerization and cracking reactions. Due to the absence of poisoning compounds, noble metals (e.g. Pt, Pd) can be employed together with a mesoporous silica-alumina support. The aim of this study was to prepare and test noble metal/silica-alumina catalysts for the hydroconversion of Fischer-Tropsch waxes. A Pd- and a Pt-based catalyst were prepared and fully characterized according to commonly used techniques. From these analyses, it was found that a higher metal dispersion and a lower total acidity characterize the Pt-based catalyst. The experimental testing demonstrated that the Pt-based catalyst is the most suitable for the hydroconversion of FT waxes since it possesses higher activity (evaluated as C22+ conversion) and higher selectivity towards the middle-distillate fraction (i.e. the desired product). Furthermore, both catalysts were tested under about 200 hours on stream showing a good stability.

    The last part of this study was devoted to the modelling of the hydroconversion reaction. Firstly, a deep literature review of the already published models was carried out. Afterwards, the considered most advanced model was implemented in a commercial simulator in order to test its prediction power with respect to the main features of the reacting system. In addition, an improved version of this model was proposed considering the variability of a stoichiometric factor, previously kept constant. The former model and its improved version were tested and compared according to a statistical study. Thanks to this, it was possible to state that the improved hydroconversion model has a slightly better prediction power.

    Finally, a comparison of the two catalysts was carried out by evaluating their kinetic constants derived from the improved model. From this point of view, the Pd-based catalyst presents stronger Langmuir adsorption constants. This could explain its lower reactivity since the involved species have a higher energy barrier prior to desorb. Moreover, this catalytic system presents a higher probability of producing isomerized fragments after a cracking after (86% on Pd, 78% on Pt on average). This suggests that more isomerization steps occur in the case of the Pd-based catalyst prior to undergo cracking reactions. This aspect could add some further explanations to its lower activity since the conversion of high boiling point fractions is slower.

  • 169.
    Lazarevic, David
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi (flyttat 20130630). CNRS Troyes University of Technology, France; Veolia Environnement Recherche et Innovation, France.
    Buclet, Nicolas
    University of Technology, Troyes.
    Brandt, Nils
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi (flyttat 20130630).
    The influence of the waste hierarchy in shaping European waste management: the case of plastic waste2010Inngår i: Regional Development Dialogue, ISSN 0250-6505, Vol. 31, nr 2, s. 124-148Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Waste management in Europe has experienced significant changes since the 1970s. The majority of Member State waste management regimes have shifted from policies based on the control of waste disposal activities, to include goals for waste prevention and recovery. The rapid increase of plastic packaging recycling in Germany had a number of unintended consequences. In the first years of the Packaging Ordinance, the majority of plastic packaging collected was exported to China, Eastern Europe, and other EU Member States due to lack of national capacity. The setting of high recycling targets for plastic packaging waste between 1991 and 1998 and the prohibition of incineration with energy recovery was a key driver of recycling technology innovation in Germany. When adopting new principles to serve as the foundation of belief, they should synchronize with the existing waste management myths of individual regions, as myths may differ from region to region illustrating different cultural ideals.

  • 170.
    Ledung, Greger
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Heterogenization of a Cobalt Porphyrin Catalyst Investigated by Scanning Probe Microscopy and X-Ray Photoelectron Spectroscopy: The Effect on Catalysis of Oxidation Reactions2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Construction of advanced materials through self-assembly on the molecular level is an important route to achieve novel functionality. Self-assembly of thiols onto gold has during the last decades shown greate promise in the creation of functional nanomaterials, such as sensors or catalysts, but for many applications silicon should be a better substrate since it offers semiconducting properties and better processing abilities in addition to being cheaper. This work describes an efficient novel method to incorporate reactive disulfide bonds onto a silica surface under mild reaction conditions. The reactive thiol groups introduced onto the silica surface will be oxidized but is then converted into highly reactive thiopyridyl groups, which can easily be utilized for further organic synthesis involving thiol-containing molecules.

    Cobalt tetraarylporphyrins with thioacetate-functionalized carbon chains on the aryl groups were synthesized (CoTPP-L) and were used as a model system for investigating catalytic activity in homogeneous and heterogeneous oxidation catalysis. For heterogeneous catalysis CoTPP-L was immobilized onto gold surfaces through thiol-gold self-assembly, and onto silica surfaces by the above mentioned disulfide exchange method.

    The properties of the molecular layers were characterized on the molecular level by means of X-ray photoelectron spectroscopy (XPS) and scanning probe microscopy (SPM). The immobilization on gold surfaces took place through the formation of multiple thiolate bonds and it could be controlled by varying the preparation scheme. More thiolate bonds form if the thioacetyl protective groups of the thiol linkers are cleaved off prior to immobilization. The CoTPP-L molecules were in all cases found to form stable disordered monolayers on gold surfaces. On silica surfaces the CoTPP-L forms patchwise multilayers.

    The catalytic performance of the heterogenized systems (CoTPP-L immobilized onto gold or silicon wafers) was evaluated and it was found that the strong inactivation observed for their homogeneous congener was avoided. As a result, the turnover number per molecule in heterogeneous catalysis was at least 100 times higher than that of the corresponding homogeneous catalyst. It is thus demonstrated that the performance of these catalysts can be dramatically improved if the catalyst arrangement can be controlled on the molecular level. Work is ongoing to extend the system to high surface area materials.

  • 171.
    Lee, Husileng
    et al.
    DUT, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Wu, Xiujuan
    DUT, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Ye, Qilun
    DUT, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Wu, Xingqiang
    DUT, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Wang, Xiaoxiao
    DUT, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Zhao, Yimeng
    DUT, State Key Lab Fine Chem, DUT KTH Joint Educ & Res Ctr Mol Devices, Dalian 116024, Peoples R China..
    Sun, Licheng
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Hierarchical CoS2/Ni3S2/CoNiOx nanorods with favorable stability at 1 A cm(-2) for electrocatalytic water oxidation2019Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 55, nr 11, s. 1564-1567Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Herein, we have reported an easily synthesized CoS2/Ni3S2/CoNiOx water oxidation catalyst with excellent catalytic activity and superior durability. The as-prepared catalyst required overpotential (eta) as low as 256 mV to exhibit a current density of 10 mA cm(-2) in 1.0 M KOH. Remarkably, it sustained a current density of 1 A cm(-2) for one week in 30% KOH solution with only 25 mV increment of eta. Thus, it is a hopeful candidate as a highly-effective water oxidation electrode in practical applications.

  • 172. Leppänen, A.
    et al.
    Kinnunen, H.
    Broström, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Enestam, Sonja
    Condensation and deposit formation in the NaCl-Na2SO4 system, an experimental and modeling study2017Konferansepaper (Annet vitenskapelig)
  • 173.
    Li, Fei
    et al.
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Du, Jian
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Li, Xiaona
    Dalian Univ Technol, Sch Environm Sci & Technol, Key Lab Ind Ecol & Environm Engn, Dalian 116024, Peoples R China..
    Shen, Junyu
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Wang, Yong
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Zhu, Yong
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Sun, Licheng
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Integration of FeOOH and Zeolitic Imidazolate Framework-Derived Nanoporous Carbon as an Efficient Electrocatalyst for Water Oxidation2018Inngår i: Advanced Energy Materials, ISSN 1614-6832, Vol. 8, nr 10, artikkel-id 1702598Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As a cost-effective catalyst for the oxygen evolution reaction (OER), the potential use of FeOOH is hindered by its intrinsic poor electron conductivity. Here, the significant enhancement of OER activity and long-term stability of electrodeposited FeOOH on zeolitic imidazolate framework-derived N-doped porous carbons (NPCs) are reported. In alkaline media, FeOOH/NPC supported on nickel foam as a 3D electrode delivers a current density of 100 mA cm(-2) at a small overpotential of 230 mV and exhibits a low Tafel slope of 33.8 mV dec(-1) as well as excellent durability, making it one of the most active OER catalysts. Such high performance is attributed to a combined effect of the excellent electron conductivity of NPC and the synergy between FeOOH and NiO derived from Ni substrate.

  • 174.
    Li, Guowei
    et al.
    Max Planck Inst Chem Phys Solids, Germany.
    Fu, Chenguang
    Max Planck Inst Chem Phys Solids, Germany.
    Wu, Jiquan
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Rao, Jiancun
    Univ Maryland, MD 20742 USA.
    Liou, Sz-Chian
    Univ Maryland, MD 20742 USA.
    Xu, Xijin
    Univ Jinan, Peoples R China.
    Shao, Baiqi
    Chinese Acad Sci, Peoples R China.
    Liu, Kai
    Chinese Acad Sci, Peoples R China.
    Liu, Enke
    Chinese Acad Sci, Peoples R China.
    Kumar, Nitesh
    Max Planck Inst Chem Phys Solids, Germany.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Gooth, Johannes
    Max Planck Inst Chem Phys Solids, Germany.
    Auffermann, Gudrun
    Max Planck Inst Chem Phys Solids, Germany.
    Sun, Yan
    Max Planck Inst Chem Phys Solids, Germany.
    Felser, Claudia
    Max Planck Inst Chem Phys Solids, Germany.
    Zhang, Baomin
    Univ Jinan, Peoples R China.
    Synergistically creating sulfur vacancies in semimetal-supported amorphous MoS2 for efficient hydrogen evolution2019Inngår i: Applied Catalysis B: Environmental, ISSN 0926-3373, E-ISSN 1873-3883, Vol. 254Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The presence of elemental vacancies in materials are inevitable according to statistical thermodynamics, which will decide the chemical and physical properties of the investigated system. However, the controlled manipulation of vacancies for specific applications is a challenge. Here we report a facile method for creating large concentrations of S vacancies in the inert basal plane of MoS2 supported on semimetal CoMoP2. With a small applied potential, S atoms can be removed in the form of H2S due to the optimized free energy of formation. The existence of vacancies favors electron injection from the electrode to the active site by decreasing the contact resistance. As a consequence, the catalytic current is increased by 221% with the vacancy-rich MoS2 as electrocatalyst for hydrogen evolution reaction (HER). A small overpotential of 75 mV is needed to deliver a current density of 10 mA cm(-2), which is considered among the best values achieved for MoS2. It is envisaged that this work may provide a new strategy for utilizing the semimetal phase for structuring MoS2 into a multi-functional material.

  • 175.
    Li, Hao
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Shang, Huan
    Cent China Normal Univ, Peoples R China.
    Shi, Yuchen
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Yakimova, Rositsa
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Syväjärvi, Mikael
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Zhang, Lizhi
    Cent China Normal Univ, Peoples R China.
    Sun, Jianwu
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Atomically manipulated proton transfer energizes water oxidation on silicon carbide photoanodes2018Inngår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, nr 47, s. 24358-24366Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surmounting the sluggish water oxidation kinetics beyond the hole-dominated thermodynamic effect is a topic of great scientific interest to establish fully renewable hydrogen technology from solar-powered water splitting. Herein, we demonstrate that the bottleneck of photoelectrochemical water oxidation can be overcome via atomic manipulation of proton transfer on the polar surfaces of silicon carbide (SiC) photoanodes. On the typical carbon-face SiC, where proton-coupled electron transfer governed the interfacial hole transfer for water oxidation, substantial energy loss was inevitable due to the highly activated proton-transfer steps. Via preferentially exposing the silicon-face, we enabled surface-catalyzed barrierless O-H breaking with a facile proton exchange and migration character. This mechanistically shifted the rate limiting step of water oxidation from sluggish proton-coupled electron transfer to a more energy-favorable electron transfer. The proof-of-concept study introduced here may open up new possibilities to design sophisticated photoelectrodes for an unbiased solar water splitting cell via surface engineering.

  • 176.
    Li, Lin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Functional Photo-electrochemical Devices for Solar Cellsand Solar Fuels Based on Molecular Components2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis concerns the development and the study of molecular functional photo-electrochemical cells (PEC) for solar cells and solar fuels.

    The first chapter gives a general introduction about photosynthesis, dye-sensitized solar cell and photo-electrochemical device for water splitting.

    The second chapter describes a TiO2-Co-catalyst electrode manufactured by a direct photo-deposition method. The electrode showed activity for electrochemical water oxidation in an electrochemical device.

    In the third chapter, a photo-electrochemical cell (PEC) with two-electrodes for visible light driven water splitting has been successfully demonstrated. One electrode was a photo-anode, which assembled a ruthenium water oxidation catalyst (complex 1) into a dye-sensitized porous nanostructured TiO2 electrode by employing a cation-exchange membrane (Nafion). The other electrode was platinum which was used as a passive cathode for proton reduction.

    In the fourth chapter, an earth abundant metal complex with an anchoring group (cobalt complex 2) was synthesized and investigated as water oxidation catalyst. This complex was further applied into a photo-anode in a PEC. The photo-anode was assembled by co-sensitization of complex 2 to a dye-sensitized porous nanostructured TiO2 electrode. The PEC device gave ca. 250 υA/cm2 photo-current and 7.2 % IPCE without applying any bias voltage, which is much higher than the reported results in the sample type of PEC. Meanwhile, we have shown that the catalytic effect is not from free cobalt ions, CoOx film or nanoparticles formed in situ by using complex 2 in the device.

    The last two chapters describe an optimization of the NiO films prepared in two steps rather than one step film and applied in p-type DSSCs. This optimized film could adsorb more dye (P1), leading to a significant light harvesting efficiency (LHE) and IPCE in DSSCs. We further combined this P1 sensitized photo-cathode with a hydrogen evolution catalyst (complex 3) and applied this photo-cathode into a PEC for visible light hydrogen evolution.

  • 177.
    Li, Qizhao
    et al.
    East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China.;East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Joint Int Res Lab Precis Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China..
    Li, Chengjie
    East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China.;East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Joint Int Res Lab Precis Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China..
    Kim, Jinseok
    Yonsei Univ, Dept Chem, Seoul 03722, South Korea.;Yonsei Univ, Spect Lab Funct Elect Syst, Seoul 03722, South Korea..
    Ishida, Masatoshi
    Kyushu Univ, Grad Sch Engn, Dept Chem & Biochem, Fukuoka, Fukuoka 8190395, Japan.;Kyushu Univ, Ctr Mol Syst, Fukuoka, Fukuoka 8190395, Japan..
    Li, Xin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Gu, Tingting
    Jiangsu Univ, Sch Chem & Chem Engn, Zhenjiang 212013, Jiangsu, Peoples R China..
    Liang, Xu
    Jiangsu Univ, Sch Chem & Chem Engn, Zhenjiang 212013, Jiangsu, Peoples R China..
    Zhu, Weihua
    Jiangsu Univ, Sch Chem & Chem Engn, Zhenjiang 212013, Jiangsu, Peoples R China..
    Ågren, Hans
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi.
    Kim, Dongho
    Yonsei Univ, Dept Chem, Seoul 03722, South Korea.;Yonsei Univ, Spect Lab Funct Elect Syst, Seoul 03722, South Korea..
    Furuta, Hiroyuki
    Kyushu Univ, Grad Sch Engn, Dept Chem & Biochem, Fukuoka, Fukuoka 8190395, Japan.;Kyushu Univ, Ctr Mol Syst, Fukuoka, Fukuoka 8190395, Japan..
    Xie, Yongshu
    East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Key Lab Adv Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China.;East China Univ Sci & Technol, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr, Joint Int Res Lab Precis Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China..
    Regioselectively Halogenated Expanded Porphyrinoids as Building Blocks for Constructing Porphyrin-Porphyrinoid Heterodyads with Tunable Energy Transfer2019Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 141, nr 13, s. 5294-5302Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Expanded porphyrins have been attracting increasing attention owing to their unique optical and electrochemical properties as well as switchable aromaticity. Toward material applications, regioselective functionalization of the expanded porphyrins at their periphery is indeed challenging due to the presence of multiple reactive sites. Herein, a set of regioselective halogenated isomers (L5-Br-A/B/C) of neo-confused isosmaragdyrin (L5) are synthesized by a combination of the halogenation reaction of L5 and sequential macrocycleto-macrocycle transformation reactions of its halogenated isomers. On this basis, the regioselectively functionalized isosmaragdyrins are utilized as building blocks for constructing multichromophoric porphyrinoids, specifically, heterodyads L5-ZnP-A/B/C, in which a common zinc porphyrin is linked at three different pyrrolic positions of isosmaragdyrins, respectively, by Sonogashira coupling reactions. The highly efficient energy cascade from porphyrin to isosmaragdyrin is elucidated using steady-state/time-resolved spectroscopies and theoretical calculations. Notably, the energy transfer processes from the porphyrin to the isosmaragdyrin moieties as well as the excitation energy transfer rates in L5-ZnP-A/B/C are highly dependent on the linking sites by through-bond and Forster-type resonance energy transfer mechanisms. The site-selective functionalization and subsequent construction of a set of heterodyads of the expanded porphyrinoid would provide opportunities for developing new materials for optoelectronic applications.

  • 178.
    Li, Yulin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik.
    Analysis of green-house gas emission in China2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Today China produces most GHG emissions in the world, which continues increasing the average temperature of the Earth. For the purpose of reducing the emission and reaching the peak of GHG emission before 2030, Chinese government promotes several policies, such as developing renewable energy, importing advanced emission reduction technology and encouraging the production and sales of new energy vehicles.

    In order to estimate the tendency of Chinese GHG emission, a review has been conducted. This review has considered the current Chinese situation, making necessary assumptions and calculating total emission in several relevant sectors independently. By adjusting several key figures, the end result of peak year may be changed.

    The review has proved that the peak year for Chinese GHG emissions will be 2035 under normal condition. If other optimized factors are considered, the peak year could be moved up.

  • 179.
    Liljenberg, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström.
    Poly(triazine imide): Growing Larger Crystallites of CrystallineCarbon Nitride and Understanding Their Dissolution2018Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Crystalline carbon nitride has been a hot topic for the last ten years because of reports claiming it could work as a photocatalyst for cheap water splitting, a catalyst for difficult reactions inorganic chemistry and the use as a potential two-dimensional semiconductor.The carbon nitride of interest in this project is poly(triazineimide) (PTI), which has a layered structure similar to graphite. Oneof the goals was to examine the synthesis parameters to try tounderstand what makes these crystallites grow. The material was

    primarily analyzed using scanning electron microscopy and powder x-ray diffraction.

    The other goal of this project was to examine the physical properties of dissolved PTI. It is currently not understood how PTI behaves in various solvents. The effect on how the freezing point depression varies in different solvents was, therefore, tested.No strong correlations of how the morphology of the produced PTIdiffered with different synthesis parameters. Freezing point measurements suggest that a solution of PTI follows Raoult's law and can be described as a true solution.

  • 180.
    Lim, Eunhee
    et al.
    University of Cambridge, England; Korea Institute Ind Technology KITECH, South Korea.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Schwartz, Erik
    Radboud University of Nijmegen, Netherlands.
    Cornelissen, Jeroen J. L. M.
    Radboud University of Nijmegen, Netherlands.
    Nolte, Roeland J. M.
    Radboud University of Nijmegen, Netherlands.
    Rowan, Alan E.
    Radboud University of Nijmegen, Netherlands.
    Greenham, Neil C.
    University of Cambridge, England.
    Do, Lee-Mi
    Elect and Telecommun Research Institute ETRI, South Korea.
    Carbazole Functionalized Isocyanide Brushes in Heterojunction Photovoltaic Devices2012Inngår i: Journal of Nanoscience and Nanotechnology, ISSN 1533-4880, E-ISSN 1533-4899, Vol. 12, nr 1, s. 503-507Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work, carbazole-containing polyisocyanide (PIACz) brushes were used for photovoltaic devices. A photovoltaic device was fabricated on top of the brushes by spin-coating a suitable acceptor and evaporating an Al cathode. Devices with a poly(N-vinylcarbazole) (PVK) bulk polymer were also prepared for comparison. Interestingly, the brushes showed better photovoltaic characteristics as compared to the blended PVK system. This is attributed to the specific morphologies of the polyisocyanide brushes, which provide a large interfacial area between the donor and acceptor for efficient photogeneration. It was found that the device performance varied according to the molecular size of the incorporated acceptors.

  • 181.
    Lindahl, Niklas
    et al.
    Chalmers Univ Technol, Dept Phys, SE-41296 Gothenburg, Sweden..
    Eriksson, Björn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Groenbeck, Henrik
    Chalmers Univ Technol, Dept Phys, SE-41296 Gothenburg, Sweden..
    Wreland Lindström, Rakel
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Lagergren, Carina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Wickman, Bjoern
    Chalmers Univ Technol, Dept Phys, SE-41296 Gothenburg, Sweden..
    Fuel Cell Measurements with Cathode Catalysts of Sputtered Pt3Y Thin Films2018Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 11, nr 9, s. 1438-1445Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fuel cells are foreseen to have an important role in sustainable energy systems, provided that catalysts with higher activity and stability are developed. In this study, highly active sputtered thin films of platinum alloyed with yttrium (Pt3Y) are deposited on commercial gas diffusion layers and their performance in a proton exchange membrane fuel cell is measured. After acid pretreatment, the alloy is found to have up to 2.5 times higher specific activity than pure platinum. The performance of Pt3Y is much higher than that of pure Pt, even if all of the alloying element was leached out from parts of the thin metal film on the porous support. This indicates that an even higher performance is expected if the structure of the Pt3Y catalyst or the support could be further improved. The results show that platinum alloyed with rare earth metals can be used as highly active cathode catalyst materials, and significantly reduce the amount of platinum needed, in real fuel cells.

  • 182.
    Lindberg, Jonas
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Electrochemical Investigation of the Reaction Mechanism in Lithium-Oxygen Batteries2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Lithium-oxygen batteries, also known as Lithium-air batteries, could possibly revolutionize energy storage as we know. By letting lithium react with ambient oxygen gas very large theoretical energy densities are possible. However, there are several challenges remaining to be solved, such as finding suitable materials and understanding the reaction, before the lithium-oxygen battery could be commercialized. The scope of this thesis is focusing on the latter of these challenges.

    Efficient ion transport between the electrodes is imperative for all batteries that need high power density and energy efficiency. Here the mass transport properties of lithium ions in several different solvents was evaluated. The results showed that the lithium  mass transport in electrolytes based on the commonly used lithium-oxygen battery solvent dimethyl sulfoxide (DMSO) was very similar to that of conventional lithium-ion battery electrolytes. However, when room temperature ionic liquids were used the performance severely decreased.

    Addition of Li salt will effect the oxygen concentration in DMSO-based electrolytes. The choice of lithium salt influenced whether the oxygen concentration increased or decreased. At one molar salt concentration the highest oxygen solubility was 68 % larger than the lowest one.

    Two model systems was used to study the electrochemical reaction: A quartz crystal microbalance and a cylindrical ultramicroelectrode. The combined usage of these systems showed that during discharge soluble lithium superoxide was produced. A consequence of this was that not all discharge product ended up on the electrode surface.

    During discharge the cylindrical ultramicroelectrodes displayed signs of passivation that previous theory could not adequately describe. Here the passivation was explained in terms of depletion of active sites. A mechanism was also proposed.

    The O2 and Li+ concentration dependencies of the discharge process were evaluated by determining the reactant reaction order under kinetic and mass transport control. Under kinetic control the system showed non-integer reaction orders with that of oxygen close to 0.5 suggesting that the current determining step involves adsorption of oxygen. At higher overpotentials, at mass transport control, the reaction order of lithium and oxygen was zero and one, respectively. These results suggest that changes in oxygen concentration will influence the current more than that of lithium.

    During charging not all of the reaction product was removed. This caused an accumulation when several cycles was examined. The charge reaction pathway involved de-lithiation and bulk oxidation, it also showed an oxygen concentration dependence.

  • 183.
    Lindbergh, Göran
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Wreland Lindström, Rakel
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Teknikbevakning av polymera bränsleceller (PEMFC) 20082008Rapport (Annet (populærvitenskap, debatt, mm))
  • 184.
    Lindelöf, Åsa
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi.
    Metangasutsläpp från deponier och osäkerheter i beräkningsmodeller kring detta2012Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    I Sverige finns uppskattningsvis mellan 4000 och 8000 stycken deponier. De flesta av deponierna är nedlagda och år 2001 fanns det 142 stycken aktiva deponier för hushållsavfall. År 2010 hade antalet minskat till 76 stycken.  Vid nedbrytning av organiskt material i deponier bildas metanhaltig deponigas som bidrar till växthuseffekten. Utsläppens omfattning prognostiseras med hjälp av beräkningsmodeller, exempelvis IPCCs. Dessa modeller fordrar att antaganden görs av exempelvis andelen gas som utvinns via gasuppsamlingsutrustningen, det organiska materialets halveringstid och avfallets sammansättning och mängd. I Sverige görs antagandet att 60 procent av deponigasen samlas upp på deponier med gasuppsamlingsutrustning. Rapportens övergripande syfte var att undersöka hur osäkerheterna i de antaganden som görs kan inverka på de prognostiserade deponigasemissionerna. Syftet var också att bedöma om metangasutsläpp från deponier utgör ett stort eller försumbart tillskott av växthusgasutsläpp i jämförelse med andra källor. Detta gjordes genom en känslighetsanalys som baserades på en litteraturstudie, IPCC- prognostiserade metanmängder samt genom intervjuer med deponiägare.

     

    Prognostiserad metangasproduktion från landets deponier jämfördes med uppskattad metangasproduktion, där det senare baserades på utvunna mängder i landet och en uppskattad utvinningsgrad på 60 procent. Prognostiserad metangasmängd jämfördes med en uppskattad mängd metan, där den senare baserades på utvunna gasmängder i landet och uppskattad utvinningsgrad. Omfattningen av emissionerna gjordes genom känslighetsanalys där utvinningsgrad hos gasuppsamlingssystemets varierades mellan 30 och 80 procent. De utvunna gasmängderna har varit relativt konstanta de senaste tio åren trots att antalet deponier med gasuppsamlingsutrustning minskat från 75 till 47 stycken och att deponeringsförbud har instiftats. Den antagna halveringstiden på 7,5 år torde därför vara för lågt ansatt vilket också styrks av den dåliga nedbrytningen i flera äldre deponier, minskade mängder deponerat avfall samt att inget organiskt material deponeras sedan 2005. Sveriges huvudsakliga metankällor är jordbrukssektorn och deponier från avfallssektorn. År 1990 var de prognostiserade utsläppen från de två sektorerna ungefär lika stora. Fram till år 2010 har de prognostiserade utsläppen från deponier halverats medan utsläpp från jordbruket ligger på ungefär samma nivå som tidigare.

     

    Ur den enskilda deponins perspektiv kan det konstateras att utvinningsgraden hos gasuppsamlingssystemet varierar i både ett kortsiktigt och i ett långsiktigt perspektiv. Beroende på när en mätning utförs kommer en viss variation uppvisas i gasutvinningssystemets utvinningsgrad dvs både emitterade och uppsamlade gasmängder varierar mellan mättillfällena.  Det kan konstateras att en stor osäkerhet byggs in i den beräknade årsproduktionen av metangas när metanmängderna beräknas med hjälp av medelvärden från ett fåtal mätningar utförda under korta mätperioder. Statistiska Centralbyrån har gjort beräkningar av den årliga utvinningsgraden. Dessa beräkningar har grundats på faktiska utvunna mängder som jämförts med beräknade totala mängder. För en enskild deponi kan skillnaderna mellan de beräknade och faktiska mängderna vara stora vilket medför att utvinningsgraden eller produktionen är svårbedömd både för den enskilda deponin och på nationell nivå.

     

    Potentialen för gasutvinning i deponier bedöms i det här examensarbetet vara större än vad som har prognostiserats. Perioden för gasuttag sträcker sig längre än vad man trott med anledning av att mycket av det organiska materialet i gamla deponier fortfarande inte har brutits ner, samt att gasproduktion fortfarande sker. Med anledning av de låga driftskostnaderna bör deponigasutvinning fortskrida så länge som det är tekniskt möjligt och ekonomiskt hållbart. Genom provtagningar av avfallet i kombination med mätningar som sträcker sig över längre perioder, skulle bättre kännedom om metangasproduktionen i deponier kunna fås.

  • 185.
    Lindström, Rakel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Kortsdottir, Katrin
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Active area determination for porous Pt-electrodes used in PEM fuel cells: Temperature and humidity effects2009Inngår i: Proton Exchange Membrane Fuel Cells 9 / [ed] T. Fuller, C. Hartnig, V. Ramani, H. Uchida, H. Gasteiger, S. Cleghorn, P. Strasser, T. Zawodzinski, D. Jones, P. Shirvanian, T. Jarvi, P. Zelenay, C. Lamy, P. Bele, 2009, s. 1211-1220Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper aim to discuss a proper measure of the electrochemical active area of carbon supported Pt nanoparticle catalyst used in polymer electrolyte membrane (PEM) fuel cells. The cyclic voltammetric determination of hydrogen under potential deposition (Hupd) and carbon monoxide monolayer oxidation (CO stripping) performed in a fuel cell at fuel cell relevant conditions are compared and the influences of operation temperature (25-80 {degree sign}C) and relative humidity (RH) (40-90% RH) are discussed. The results show that both the shape and the charge of the Hupd are strongly dependent on operating conditions. However, for the CO stripping experiments only a negative shift in potential with increasing temperature or humidity was observed in accordance with results from aqueous electrolytes, whereas the charges for CO monolayer oxidation were almost constant for the temperatures investigated.

  • 186.
    Linnas, Ingrid
    KTH, Skolan för kemivetenskap (CHE).
    Catalyst performance in high temperature catalytic combustion2012Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis was carried out in co-operation between KTH- Royal Institute of Technology, Tallinn University of Technology and ReformTech Heating Technologies Sweden AB. The purpose of this thesis was to evaluate catalyst performance in a catalytic heater developed by ReformTech Heating Technologies Sweden AB. Different catalysts were tested for the combustion of diesel at 5 KW adiabatic power during 1 hour. The catalysts were evaluated based on the temperature profiles, emission results and mechanical durability. The catalyst with ceramic support showed the most promising results for this application with the highest mechanical durability and exhaust emissions below 0,5 ppm for diesel and CO, NOX content in the exhaust gas was negligible .

  • 187.
    Liora, Jackson
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för analytisk farmaceutisk kemi.
    Characterization of the equine metabolites of LGD-4033 in urine using UHPLC-MS(/MS) for doping control purposes2017Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The aim of this project was to study and characterize the metabolitesof LGD-4033 in equine urine, with the final aim of using the results indoping controls in equestrian sports. Urine samples had been taken atdifferent points in time from three horses that had received thesubstance intravenously. The samples were both directly analysed usinga so called dilute-and-shoot approach and were also prepared with amixed mode anion exchange solid phase extraction. All analysis weredone with UHPLC-ESI-MS(/MS) in negative mode. A total of eightmetabolites were found, which were all combinations of phase Ihydroxylation and/or phase II glucuronidation. Of these a total of four(one that is both monohydroxylated and glucuronidated, one that isdihydroxylated, as well as two glucuronidated metabolites) would besuitable for doping control.

  • 188.
    Liu, Jia
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi. Northeast Normal Univ, Natl & Local United Engn Lab Power Batteries, Fac Chem, Changchun 130024, Peoples R China..
    Ma, Yue
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Roberts, Matthew
    Univ Oxford, Dept Mat, Parks Rd, Oxford OX1 3PH, England..
    Gustafsson, Torbjörn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Edström, Kristina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Zhu, Jiefang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Highly efficient Ru/MnO2 nano-catalysts for Li-O2 batteries: Quantitative analysis of catalytic Li2O2 decomposition by operando synchrotron X-ray diffraction2017Inngår i: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 352, s. 208-215Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In-situ or operando quantitative analysis is very important for Li-O2 batteries, in order to properly, accurately and comprehensively evaluate electrocatalysts and characterize Li-O2 electrochemistry in real-time. Synchrotron XRD can provide much higher X-ray intensity and time resolution than traditional in-house diffractometers, and therefore can contribute to quantitative analysis for Li-O2 batteries. Here, operando synchrotron XRD is further developed to quantitatively study Li-O2 batteries with nano catalysts, Ru/MnO2. The time-resolved oxygen evolution reaction (OER) kinetics for Li-O2 cells with Ru/MNT was systematically investigated using operando synchrotron radiation powder X-ray diffraction (SR-PXD). Li2O2 decomposition in the electrodes with Ru/MNT catalysts during galvanostatic and potentiostatic charge processes followed pseudo-zero-order kinetics and showed ideal Coulombic efficiency (close to 100%). Furthermore, it was found that the OER kinetics for a cell with 2 wt% Ru/MNT charged at a constant potential of 4.3 V was even faster than that for a cell with the same amount of pure Ru nanoparticles, which have been considered as a highly active catalyst for Li-O2 batteries. These results indicated that Ru/MNT with a special nanostructure represented a very efficient electrocatalyst for promoting the OER in Li-O2 batteries. We also demonstrate that synchrotron radiation XRD can "highlight" a way to quantitative analysis for Li-O2 batteries.

  • 189.
    Liu, Longcheng
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Neretnieks, Ivars
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Shahkarami, Pirouz
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Meng, Shuo
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Moreno, Luis
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Solute transport along a single fracture in a porous rock: a simple analytical solution and its extension for modeling velocity dispersion2017Inngår i: Hydrogeology Journal, ISSN 1431-2174, E-ISSN 1435-0157Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simple and robust solution is developed for the problem of solute transport along a single fracture in a porous rock. The solution is referred to as the solution to the single-flow-path model and takes the form of a convolution of two functions. The first function is the probability density function of residence-time distribution of a conservative solute in the fracture-only system as if the rock matrix is impermeable. The second function is the response of the fracture-matrix system to the input source when Fickian-type dispersion is completely neglected; thus, the effects of Fickian-type dispersion and matrix diffusion have been decoupled. It is also found that the solution can be understood in a way in line with the concept of velocity dispersion in fractured rocks. The solution is therefore extended into more general cases to also account for velocity variation between the channels. This leads to a development of the multi-channel model followed by detailed statistical descriptions of channel properties and sensitivity analysis of the model upon changes in the model key parameters. The simulation results obtained by the multi-channel model in this study fairly well agree with what is often observed in field experiments—i.e. the unchanged Peclet number with distance, which cannot be predicted by the classical advection-dispersion equation. In light of the findings from the aforementioned analysis, it is suggested that forced-gradient experiments can result in considerably different estimates of dispersivity compared to what can be found in natural-gradient systems for typical channel widths.

  • 190.
    Lloyd Spetz, Anita
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Darmastuti, Zhafira
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Bjorklund, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Bur, Christian
    Saarland University, Saarbrücken, Germany.
    Schütze, Andreas
    Saarland University, Saarbrücken, Germany.
    Huotari, Joni
    University of Oulu, Finland.
    Jantunen, Heli
    University of Oulu, Finland.
    Lindqvist, Niclas
    Alstom Power AB, Växjö, Sweden.
    Improved chemical sensors track and control emissions2013Annet (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Sensitive, low-cost silicon carbide-based gas sensors can detect toxic emissions and hazardous nanoparticulate matter in previously untenable environments.

  • 191.
    Lloyd Spetz, Anita
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Darmastuti, Zhafira
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Bur, Christian
    Saarland University, Saarbrücken, Germany.
    Huotari, Joni
    University of Oulu, Finland.
    Bjorklund, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Lindqvist, Niclas
    Alstom Power AB, Växjö, Sweden.
    Lappalainen, Jyrki
    University of Oulu, Finland.
    Jantunen, Heli
    University of Oulu, Finland.
    Schütze, Andreas
    Saarland University, Saarbrücken, Germany.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Chemical sensor systems for environmental and emission control2013Inngår i: Proc. SPIE Defence, Security + Sensors, 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Focusing on environment and health aspects, the importance of monitoring and controlling dangerous gases and particulate matter increases. For this purpose we present a new version of silicon carbide based gas sensors with improved properties and suitable for high temperature and harsh environments such as power plants or car exhausts. Development of sulfur dioxide sensors for a power plant application is described as well as sensors for detection of ammonia in connection with the SCR process where urea is converted to ammonia, which reduces nitric oxide components in the exhausts. We also describe progress on nanoparticle detection, especially related to detection of the content of adsorbed particles through heating and detection of emitted molecules by a sensor array. Some results are also presented from impedance spectroscopy for detection of the concentration of nanoparticles but with the potential to reveal more details about the particles such as shape and kind of particles. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  • 192.
    Lloyd Spetz, Anita
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Huotari, Joni
    University of Oulu, Finland.
    Bur, Christian
    Saarland University, Saarbrücken, Germany.
    Bjorklund, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Lappalainen, Jyrki
    University of Oulu, Finland.
    Jantunen, Heli
    University of Oulu, Finland.
    Schütze, Andreas
    Saarland University, Saarbrücken, Germany.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Chemical sensor systems for emission control from combustions2013Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 187, nr SI, s. 184-190Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Environmental and health concern has increased the importance to monitor and control emissions like toxic gases and particulate matter from combustion processes. The silicon carbide-field effect transistor (SiC-FET) technology offers versatile and powerful sensors for gas detection also in combination with combustion of particles. Emission control has been demonstrated e. g. for small and medium sized power plants and diesel exhausts. The potential danger of nanoparticles makes such detectors interesting not only for detection of concentration and size of particles but also detection of the content of particles. Due to the possibility of operating the sensor devices in different independent modes (e. g. temperature- and bias-modulated) the SiC-FET technology also lends itself for the future development of sensor adaptation, self-diagnosis and auto calibration, which is expected to improve the performance of such a combined gas/particle sensor system. Here we report progress on the sensor technology itself, the application of a sensor system as an alarm for ammonia emission and preliminary results of particle detection in diesel exhausts and particles from a power plant and a steel plant.

  • 193.
    Lloyd Spetz, Anita
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Huotari, Joni
    University of Oulu, Finland.
    Bur, Christian
    Saarland University, Saarbrücken, Germany.
    Lappalainen, Jyrki
    University of Oulu, Finland.
    Schütze, Andreas
    Saarland University, Saarbrücken, Germany.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska högskolan.
    Chemical sensor systems for emission control from combustions2012Inngår i: IMCS 2012, 2012, s. 635-638Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Environmental and health concern has increased the importance to monitor and control emissions from combustion processes like toxic gases and particulate matter. The SiC-FET technology offers versatile and powerful sensors for gas detection also in combination with combustion of particles. Emission control has been demonstrated e.g. for small and medium sized power plants and diesel exhausts. The potential danger of nanoparticles makes such detectors interesting not only for detection of concentration and size of particles but also detection of the content of particles. The SiC-FET technology lends itself for smart sensing and smart data evaluation, which largely improves the information from such a sensor system. Here we report progress on the sensor technology itself, the application of a sensor system as an alarm for ammonia emission and preliminary results of particle detection.

  • 194.
    Lloyd Spetz, Anita
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten. Microelectronics and Material Physics Laboratories, University of Oulu, Finland.
    Sobocinski, Maciej
    Microelectronics and Material Physics Laboratories, University of Oulu, Finland.
    Halonen, Niina
    Microelectronics and Material Physics Laboratories, University of Oulu, Finland.
    Puglisi, Donatella
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten.
    Juuti, Jari
    Microelectronics and Material Physics Laboratories, University of Oulu, Finland.
    Jantunen, Heli
    Microelectronics and Material Physics Laboratories, University of Oulu, Finland.
    Andersson, Mike
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad sensorvetenskap. Linköpings universitet, Tekniska fakulteten. Microelectronics and Material Physics Laboratories, University of Oulu, Finland.
    LTCC, new packaging approach for toxic gas and particle detection2015Inngår i: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 120, s. 484-487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Packaging of chemical sensors is still an area, which is not much explored. Low temperature co-fired ceramic, LTCC, packaging offers large advantages in terms of 3D design, integration of advanced functionality and fast processing. SiC based FET gas sensors are possible to integrate directly in the LTCC co-firing process at 850 °C, whereby both high temperature and other advanced applications like ultra-low detection of toxic gases are greatly improved. The LTCC packaging is also used for development of particle detectors as well as packaging for an electrical method to detect toxic effect on cells by particles.

  • 195.
    Lozano, Rodrigo
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för industriell ekonomi, industridesign och maskinteknik, Industriell ekonomi. Högskolan i Gävle, Centrum för logistik och innovativ produktion.
    Chemical Engineering and Sustainability: the need for holistic education and practice2019Konferansepaper (Annet vitenskapelig)
  • 196.
    Lu, Huiran
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Hagberg, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Cornell, Ann M.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Flexible and Lightweight Lithium-Ion Batteries Based on Cellulose Nanofibrils and Carbon Fibers2018Inngår i: BATTERIES-BASEL, ISSN 2313-0105, Vol. 4, nr 2, artikkel-id 17Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Flexible, low-weight electrodes with integrated current collectors based on chopped polyacrylonitrile carbon fibers (CF) were produced using an easy, aqueous fabrication process, where only 4 wt% of TEMPO-oxidized cellulose nanofibrils (CNF) were used as the binder. A flexible full cell was assembled based on a LiFePO4 (LFP) positive electrode with a CF current collector and a current collector-free CF negative electrode. The cell exhibited a stable specific capacity of 121 mAh g(-1) based on the LFP weight. The CF in the negative electrode acted simultaneously as active material and current collector, which has a significant positive impact on energy density. Stable specific capacities of the CF/CNF negative electrode of 267 mAh g(-1) at 0.1 C and 150 mAh g(-1) at 1 C are demonstrated. The LFP/CNF with CF/CNF, as the current collector positive electrode (LFP-CF), exhibited a good rate performance with a capacity of -150 mAh g(-1) at 0.1 C and 133 mAh g(-1) at 1 C. The polarization of the LFP-CF electrode was similar to that of a commercial Quallion LFP electrode, while much lower compared to a flexible LFP/CNF electrode with Al foil as the current collector. This is ascribed to good contact between the CF and the active material.

  • 197.
    Lualdi, Matteo
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Fischer-Tropsch Synthesis over Cobalt-based Catalysts for BTL applications2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Fischer-Tropsch synthesis is a commercial technology that allows converting synthesis gas, a mixture of CO and H2, into fuels and chemicals. This process could be one of the actors in the reduction of oil dependency of the transportation sector. In fact, it has great potential for producing synthetic fuels also from renewable sources, such as biomass, after its thermochemical conversion (gasification) into synthesis gas. Concerning the quality of a diesel fuel produced with this technology, it has a lower local environmental impact than conventional diesel, since it is practically free of sulphur and nitrogen compounds and yields lower exhaust emissions of hydrocarbons, CO and particulates. The present study focuses on the use of cobalt-based catalysts for the production of diesel. In particular, it looks upon correlation between product selectivities when varying the catalyst properties and the effect of process parameters, such as a low H2/CO ratio, typical of a biomass-derived synthesis gas, and the water partial pressure.

    Different cobalt-based catalysts, with different properties, such as conventional 3-dimensional porous network supports (γ-Al2O3, α-Al2O3, TiO2, SiO2), Co-loading, preparation technique, etc., were investigated in the Fischer–Tropsch reaction at industrially relevant process conditions. For a set of process conditions, a linear relationship seems to exist between the selectivity to methane (and other light products) and higher hydrocarbons (identified by the industrially relevant parameter SC5+, selectivity to hydrocarbons with more than 4 carbon atoms) indicating a common precursor.

    Ordered mesoporous materials (SBA-15), characterized by a 1-dimensional mesoporous network, were tested as model supports and showed the possibility of occurrence of CO-diffusion limitations at diffusion distances much shorter than those required for conventional 3-dimensional porous network supports. The linear relationship mentioned above, derived for conventional supports, was shown to be an efficient tool for indicating whether measured selectivities are affected by CO-diffusion limitations. Some of the catalysts were exposed to H2-poor syngas and to external water addition and the effects on the selectivity relationships were investigated.

    Furthermore, the possibility of internal water-gas shift of a H2-poor syngas with mixtures of Co/γ-Al2O3 and a Cu/ZnO/Al2O3 catalyst was investigated both as a technical solution for direct use of a model bio-syngas in the Fischer-Tropsch synthesis, and as a means to study the effect of indigenous water removal on the reaction rate to hydrocarbons. It was found that removal of indigenously produced water slows down the reaction rate significantly. Lastly, the effect of water partial pressure on the Fischer–Tropsch rate of the Co catalyst supported on narrow-pore γ-Al2O3, on its own, was studied. Inlet water partial pressure was varied by external water vapor addition at different H2/CO molar ratios ranging from 1 to 3. The effect of water showed to be positive on the rate for all the H2/CO ratios, but more significantly at H2-poor conditions. The nature of this positive effect on the rate seems to be unrelated to changes in amounts of amorphous polymeric carbon detectable by temperature-programmed hydrogenation of the spent catalyst.

  • 198.
    Lualdi, Matteo
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Lögdberg, Sara
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Boutonnet, Magali
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Järås, Sven
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    On the effect of water on the Fischer-Tropsch rate over a Co-based catalyst: The influence of the H2/CO ratio2013Inngår i: Catalysis Today, ISSN 0920-5861, E-ISSN 1873-4308, Vol. 214, s. 25-29Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of water partial pressure on the Fischer-Tropsch (FT) rate of a cobalt catalyst supported on narrow-pore γ-Al2O3 was investigated at industrially relevant process conditions (483 K, 30 bar, pellet size: 53-90 μm). Inlet water partial pressure was varied up to 9 bar by external water vapour addition at different H2/CO molar ratios ranging from 1 to 3. The effect of water was found to be positive on FT-rate independently of the H2/CO ratio, but more significantly at H 2-poor condition. Temperature-programmed hydrogenation (TPH) was used to verify the presence of unreactive carbon species on the catalyst after 22 h on stream at the different conditions with and without exposure to about 9 bar water. A higher temperature feature that could be associated to amorphous polymeric carbon was detected at H2-poor conditions but remained unchanged upon 2 h of water exposure which did not result in a change in the amount of amorphous polymeric carbon detectable by TPH.

  • 199.
    Lualdi, Matteo
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Lögdberg, Sara
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Di Carlo, G.
    Järås, Sven
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Boutonnet, Magali
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Venezia, A. M.
    Blekkan, E. A.
    Holmen, A.
    Evidence for diffusion-controlled hydrocarbon selectivities in the fischer-tropsch synthesis over cobalt supported on ordered mesoporous silica2011Inngår i: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 54, nr 16-18, s. 1175-1184Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of four cobalt-based catalysts (two of which promoted with ruthenium) supported on SiO2 or SBA-15 were prepared and tested in the Fischer-Tropsch synthesis at industrially relevant process conditions (483 K, 20 bar, H2/CO ratio = 2.1, pellet size: 53-90 μm). The catalysts were characterized by N2-adsorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), H2-chemisorption and transmission electron microscopy (TEM). Ru as promoter enhanced the activity but not the selectivity to long-chain hydrocarbons ({S}-{C}-{ 5+}). The {{S}}-{{C}}-{5+}} values of the SBA-supported catalysts were very low, especially at low conversion levels (i.e. low water partial pressure), suggesting that CO diffusion limitation increased the H2/CO ratio inside the 1-dimensional (1-D) porous network. A superimposition of the selectivity results on the correlations found in our recent study, derived for Co-based catalysts supported on γ-Al2O3, α-Al2O3 and TiO2 free from diffusion limitations, was made. While the SiO2-supported catalysts with a 3-D porous structure followed the correlations, the SBA-catalysts deviated significantly at low conversions, giving a further indication that the selectivity results of these catalysts were affected by CO diffusion limitations. Hence, it may be concluded that the kinetically significant diffusion distances (i.e. those long enough to cause an intrapore H 2/CO ratio higher than that of the bulk gas phase) are probably much shorter for 1-D porous networks than for conventional 3-D supports. This is explained by a significantly lower effective diffusivity in 1-D porous networks. The potential of using the correlations between non-ASF distributed hydrocarbons and C5+, to give insight on the occurrence of diffusion limitations, was confirmed by superimposing data from the literature that were anticipated to be influenced by CO diffusion limitations.

  • 200.
    Lualdi, Matteo
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Lögdberg, Sara
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Regali, Francesco
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Boutonnet, Magali
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Järås, Sven
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Investigation of mixtures of a Co-based catalyst and a Cu-based catalyst for the fischer-tropsch synthesis with Bio-Syngas: The importance of indigenous water2011Inngår i: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 54, nr 13-15, s. 977-985Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A series of different mechanical mixtures of a narrow-pore Co/γ-Al2O3 catalyst and a Cu-based WGScatalyst has been investigated in the low-temperature Fischer-Tropsch synthesis (483 K, 20 bar) with a model bio-syngas (H2/CO = 1.0) in a fixed-bed reactor. The higher the fraction of WGS-catalyst in the mixture, the lower is the Co-catalyst-time yield to hydrocarbons. This is ascribed to a strong positive kinetic effect of water on the Fischer-Tropsch rate of the Co-catalyst, showing the importance of the indigenously produced water, especially in fixed-bed reactors where the partial pressure of water is zero at the reactor inlet. A preliminary kinetic modeling suggests that the reaction order in PH2O is 0.3 for the Co/γ-Al2O3 catalyst in the range of the studied reactor-average partial pressures of water (i.e., 0.04-1.2 bar).

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