Pd–Cu/HOPG and Pd–Ag/HOPG Model Catalysts in CO and Methanol Oxidations at Submillibar Pressures

The regularities of formation of alloyed Pd–Cu bimetallic particles deposited on highly oriented pyrolytic graphite (HOPG) were studied by STM and synchrotron-radiation-based XPS. Their chemical composition, structure, and the ranges of thermal stability under ultrahigh vacuum were determined. The Pd–Cu/HOPG model catalysts, as well as the Pd–Ag/HOPG samples whose preparation procedure was tested earlier, exhibited catalytic activity in CO and methanol oxidations at pressures typical of in situ XPS experiments and were stable at the temperatures of the catalytic reaction.