Reshaping CuO on silica to generate a highly active Cu/SiO2 catalyst

Abstract

Reduction–oxidation treatment [RO] of an impregnated CuO/SiO₂ catalyst has been found to be effective in re-dispersing CuO particles on the support. During the process, CuO was actually reshaped within a confined area on silica, forming an annular morphology consisting of highly dispersed nano CuO particles. The reshaping might happen during the oxidation process following the reduction step, while no re-dispersion could be observed by applying the oxidation step alone. After activation with H₂, the RO treated samples demonstrated improved catalytic activity for methanol decomposition. These findings clearly indicate that the “shape” of CuO can be memorized during the activation process, resulting in the formation of a specific Cu metal and thus demonstrating different catalytic activities. Such a memory effect correlates the catalytic performance with the characterization data of CuO directly, which has the potential to provide a convenient approach for further catalyst development.