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

摘要

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 N-2 and H-2 contained Pd-Ag alloy and Pd particles immobilized on CeO2. The Pd-0-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 O-2; 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.