Kinetics and Mechanism of the Low-Temperature Oxidation of Carbon Monoxide with Oxygen on a PdCl2-CuCl2/γ-Al2O3 Catalyst

A systematic study of the kinetics of the low-temperature oxidation of carbon monoxide with oxygen on a PdCl2-CuCl2/gamma-Al2O3 supported catalyst was carried out over a wide range of the partial pressures of oxygen, water, and CO in order to test hypotheses on the reaction mechanism. It was shown that, as the temperature was increased from 20 to 38A degrees C, rate of formation of CO2 decreased and the apparent activation energy was about-40 kJ/mol. The hypotheses of different degrees of complexity concerning the reaction mechanism were formulated based on physicochemical data and a Langmuir-Hinshelwood model. Mechanisms in which carbon dioxide is formed on the interaction of the surface Pd(I) and Pd(II) complexes that include carbon monoxide and water with the surface complex of Cu(I) that coordinates oxygen were recognized as the most probable.