Synthesis And Characterization Of Noble Metal Nanoparticle Impregnated Metal-Organic Frameworks
Metal-Organic frameworks (MOF) is a new class of materials that are porous and crystalline. The materials are made of inorganic coordination centers linked together by organic molecules. MOFs have the advantage of the combination of inorganic units connected with highly manipulative organic molecules. The result is materials that can be specifically designed for the area of application. The disadvantage of MOFs is the low thermal stability which leads to decomposition of the framework at higher temper- atures. The industrial applications of MOFs are few, but research for the use of MOFs for gas storage, separation and catalysis is being done.
MOFs are porous and have high surface areas and this makes the MOFs interesting candidates as heterogenous catalysts with active nanoaparti- cles in the framework. The pores in the framework can define the size of the nanoparticles and also function as molecular sieves and thereby in- troduce catalytic selectivity on the reactant, intermediate and products if the catalytic process is carried out in the pores. The goal of this Masters thesis is to prepare new catalysts with gold or palladium nanoparticles deposited on the UIO-66 framework and the characterization and testing of these.
The metal-organic frameworks MOF-5 and UIO-66 have been synthesized. Gold was deposited onto the UIO-66 framework by impregnation deposi- tion, reduction and encapsulation of pre-made gold nanoparticles. Palla- dium was deposited onto the UIO-66 framework by reduction deposition. The materials have been characterized by X-ray diffraction, adsorption desorption experiments, inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy both in situ and ex situ. The Pd-UIO- 66 has been tested towards catalytic activity of the Sonogashira, Suzuki-
Miyaura and Mizoroki-Heck reactions normally performed by organopalladium complexes.
In this thesis the investigated methods for gold deposition gave low loading levels of gold (at best 0.39 wt%) on the framework and the particle sizes detected were too large for catalytic activity. The palladium loading levels were 2.34 wt% and 2.48 wt%. The Pd-UIO-66 showed catalytic activity for the Sonogashira, Suzuki-Miyaura and Mizoroki-Heck reactions, which has not been previously reported. However the catalyst was found to decompose after the work up.
Place, publisher, year, edition, pages
Institutt for kjemi , 2013. , 130 p.
IdentifiersURN: urn:nbn:no:ntnu:diva-21161Local ID: ntnudaim:7657OAI: oai:DiVA.org:ntnu-21161DiVA: diva2:631298
Mathisen, Karina, FørsteamanuensisGautun, Odd Reidar