Mechanism of CO oxidation over CuO/CeO2 catalysts

A mechanistic study of the CO oxidation reaction over copper–cerium catalysts was performed based on our own results and information available in literature. The fit of parameters was carried out with kinetic information obtained ad-hoc. Two possible mechanisms whose main difference is the role of copper were proposed. The first one postulates changes in the oxidation state of both cations (cerium and copper) while, in the second mechanism, it was assumed that the redox cycle only occurs for the ceria component. The results allow to conclude that the catalytic cycle involves both redox couples (Ce4+/Ce3+ and Cu2+/Cu1+). The kinetic expression derived from this mechanism consists of five constants and is able to accurately predict the behavior of the reactor in different reaction conditions.