Support structure effect on CO oxidation: A comparative study on SiO2 nanospheres and CeO2 nanorods supported CuOx catalysts

The effect of support reducibility and reduction treatment was studied in SiO2 nanospheres and CeO2 nanorods supported CuOx (0 ≤ x ≤ 1) catalysts on CO oxidation. CuO nanoparticles were impregnated on SiO2 nanospheres and CeO2 nanorods using thermal decomposition method and then the samples were oxidized in air at different temperatures (400-600 °C). The sample oxidized at 400 °C was also further reduced under hydrogen atmosphere to compare the effect of reduction treatment on the catalytic activity. Detailed XRD, Raman, H2-TPR, and CO oxidation analyses were carried out to understand the effect of CuOx-support interaction and different CuOx species on the catalytic performance. Compared to SiO2 nanospheres supported CuOx catalysts, both CuO/CeO2 and reduced CuOx/CeO2 catalysts exhibited superior catalytic performance in terms of CO conversion and low-temperature hydrogen consumption. The enhanced activity of CeO2 nanorods supported CuOx catalysts was correlated strongly to the surface defects on CeO2 nanorods and interfacial structures.