Au添加促进Pd/SBA-15催化剂的N2O分解研究

Along with the intensive research in gold catalysis, gold-containing bimetallic nanoparticles have also been investigated for a better understanding of the catalytic behavior of gold catalysts. Au-Pd alloy catalysts are of particular interest among them, since they have been found to exhibit superior performance over the monometallic ones in synthesis of H2O2 from H2 and O2, production of vinyl acetate from acetic acid, as well as the selective oxidation of alcohols. In this work, a new reaction, N2O decomposition, was explored for Au-Pd alloy catalysts. Highly dispersed Au-Pd alloy nanoparticles were for the first time synthesized on the SBA-15 support, and the average particle sizes were only 1~2 nm, as revealed by XRD and TEM. The dispersion of Pd, determined by H2 chemisorption, was found to be varied with the Au/Pd ratio. When the Au/Pd molar ratio was smaller than 0.1, the presence of gold caused a remarkable increase of the Pd dispersion, and thus the catalytic activity for N2O decomposition was enhanced. On the contrary, the presence of excess amount of gold led to a rapid decrease of the Pd dispersion, and the activity was accordingly lowered