Ruthenium(0) nanoparticles supported on hafnia: a highly active and long-lived catalyst in hydrolytic dehydrogenation of ammonia borane

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2016

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Kalkan, Elif Betül

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Transition metal(0) nanoparticles are highly active and selective catalyst. When stabilized in organic or aqueous solutions, they can catalyze many reactions. The catalytic activity of metal(0) nanoparticles depends on the particle size and size distribution. However, transition metal(0) nanoparticles have tendency for aggregation to larger particles, ultimately to bulk metal. Metal(0) nanoparticles can be stabilized against aggregation by supporting on the oxide surface. In this project, nanopowder hafnia (HfO2) was used as support for the stabilization of ruthenium(0) nanoparticles which is found to be one of the most active catalysts in hydrogen release from ammonia borane. Ruthenium(III) cations were impregnated on the surface of HfO2 and then reduced by sodium borohydride in aqueous solution. Next, ruthenium(0) nanoparticles were used in the catalytic hydrolysis of ammonia borane. Ruthenium(0) nanoparticles supported on hafnia were isolated from the reaction solution by centrifugation and characterized by a combination of advanced analytical techniques including ICP-OES, BET, XRD, SEM, SEM-EDS, TEM, and XPS. Ruthenium(0) nanoparticles supported on hafnia were tested as catalyst in hydrogen generation from the hydrolysis of ammonia borane at ambient temperature. The kinetics of catalytic hydrolysis were studied depending on the catalyst concentration, metal loading of the support and temperature.

Subject Keywords

Ruthenium., Ammonia., Boranes., Hydrolysis., Nanoparticles.

URI

http://etd.lib.metu.edu.tr/upload/12620468/index.pdf
https://hdl.handle.net/11511/25859

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

E. B. Kalkan, “Ruthenium(0) nanoparticles supported on hafnia: a highly active and long-lived catalyst in hydrolytic dehydrogenation of ammonia borane,” M.S. - Master of Science, Middle East Technical University, 2016.