(57r) Study of Isopropanol Oxidation On Au-Pd/SiO2 Catalysts Using Temperature Programmed Techniques

Au-Pd/SiO2 catalyst are bimetallic catalyst that are prepared using electroless deposition, in which the second metal, in our case Au, will be deposited on the surface of a catalytically primary, primary metal surface (in our case Pd). Catalyst with different Au coverage will be synthesized in order to study the interaction of isopropanol and acetone with the catalyst. Temperature program desorption (TPD) will be performed in order to study the adsorption properties of the catalyst towards isopropanol and acetone. TPD studies will also be performed for the dehydrogenation of isopropanol into acetone for the same bimetallic catalyst. A TPD study for isopropanol and acetone are carried out since is desired to understand the interaction with the catalyst before studying the reaction. The TPD studies for isopropanol and acetone shows maxima adsorption at certain Au coverage, then the adsorption decreases as the Au coverage continue to increase. The same behavior is noticed for the temperature of maximum desorption, for isopropanol and acetone. It was determined form the TPD that, the amount of acetone adsorbed on the catalyst is greater than for isopropanol in which the fractional Au coverage is less than 0.5, for greater coverage, isopropanol adsorption is greater. The dehydration of isopropanol was studied on Pd/SiO2 at different reaction temperature. After the reaction being carried out, TPD studies where performed in order to determine if materials strongly adsorbed on the catalyst. For low reaction temperatures (lower than TMD of acetone for the catalysts studied), the activity of the catalyst is low and also deactivation is present, since acetone is adsorbed on the catalyst. For reaction temperatures higher than TMD higher catalyst activity is achieved and few or no appreciable deactivation is shown, which means that little or none acetone was present on the catalyst when the TPD was performed.