Influence of the structure and morphology of CuO supports on the amount and properties of copper–cerium interfacial sites in inverse CeO2/CuO catalysts

•CeO2 is distributed on CuO supports with different morphologies.•Catalytic performance is related to BET, reduction temperature and Ce3+ content.•CuO particles are reduced into metallic copper after the reaction.•Crystallite sizes of CeO2 and CuO both increase via regeneration.•Improvement of structure and morphology of CuO support.

The CuO supports with different morphologies were prepared and the inverse CeO2/CuO catalysts were synthesized by the impregnation method. The catalysts were characterized via SEM, XRD, H2-TPR, in situ DRIFTS, XPS, TEM and N2 adsorption–desorption techniques. It is found that the CeO2/CuO-X catalysts present good catalytic performance in the CO–PROX reaction. Catalytic performance is related to BET specific surface area, Ce3+ content and reduction temperature of CuO. Cu+ species is CO adsorption site over the CeO2/CuO catalysts. The carbonate and hydrogen carbonate species cover the surface of CeO2/CuO catalysts at high temperature, and these species could cause the deactivation of the catalysts. The CuO particles are reduced into the metallic copper with large crystallite sizes after the reaction. The metallic copper is oxidized into CuO again, while the crystallite sizes of CeO2 and CuO both increase via regeneration. There are two possible ways to solve the problem of deactivation. One is to control the reaction temperature, and the other is to prevent the generation of metallic copper by promoting structure and morphology of the CuO support.

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