Enhanced CO Oxidation of Supported Cu/In2O3 Catalysts: The Phase Effect

Low-temperature catalytic oxidation has emerged as one of the most effective methods for removing carbon monoxide due to its economic feasibility. Copper-based (Cu-based) catalysts are increasingly regarded as viable alternatives to noble metal catalysts. While the incorporation of indium (In) into Cu-based catalysts has gained popularity, the impact of the In oxide (In2O3) phase on catalyst performance remains unclear. In this study, we prepared two different In2O3 with cubic (cb) and rhombohedral (rh) phases. Cu is supported on In2O3 via the impregnation method. The Cu/In2O3 catalyst with a cubic phase exhibited a higher CO oxidation activity (T90 = 122 °C). The primary reason for this enhanced activity is that the cubic phase of the In2O3 support promoted the generation of the surface Cu+ species. Based on the in situ DRIFTS results, Cu+ species and Cu+-CO species serve as active sites and active intermediates, respectively, in the CO oxidation reaction.