Effect of the Chemical Atmosphere of the Thermolysis of the Complex PdAg2(OAc)4(HOAc)4 on the Formation of Active Centers in Pd–Ag/CeO2 Catalysts for the Low-Temperature Oxidation of Carbon Monoxide

Abstract

Abstract: The Pd–Ag/CeO2 catalysts were prepared by the impregnation of highly dispersed CeO2 with a solution of the heteroatomic complex PdAg2(OAc)4(HOAc)4. Samples obtained after the thermolysis of PdAg2(OAc)4(HOAc)4 in N2 and H2 contained Pd–Ag alloy and Pd particles immobilized on CeO2. The Pd0–CeO2 metal oxide centers formed at the interface were highly active in the low-temperature reaction of CO oxidation. The particles of Pd were absent from the Pd–Ag/CeO2 sample prepared by the decomposition of PdAg2(OAc)4(HOAc)4 in an atmosphere of O2; in this case, a significant portion of the Pd–Ag phase was covered with a film of CeO2, which dramatically slowed down the rate of reaction at low temperatures.