NO reduction by CO over CoO_x/CeO₂ catalysts: Effect of support calcination temperature on activity

CeO₂ supported CoO_x catalysts showed promising results in many NO reduction processes including NO reduction by CO. In this work, a series of CeO₂ supports with different calcination temperatures (as received-800 °C calcination) were prepared, followed by the synthesis of a series of CoO_x/CeO₂ catalysts with a surface density of 2.5 Co/nm² using the incipient wetness impregnation method. To understand the physicochemical properties of catalysts, various characterizations techniques, including BET, Raman spectroscopy, XRD, and H₂-TPR, were performed. The results showed that as calcination temperature increased, physical properties of supporting materials were changed. Surface CoO_x improved the reducibility of CeO₂, but it was not affected by the support calcination temperatures confirmed by H₂-TPR. The presence of CoO_x was crucial to enhance the catalytic activity during the NO reduction by CO reaction, rather than physical properties (surface area, pore size, particle size) of the catalyst.