Effect of copper loading on synergism in CuO/CeO2 nanorod catalysts for toluene combustion

CuO/CeO2 catalysts were widely studied as an alternative to precious metal catalysts, and the Cu-Ce synergy was essential to improve the catalytic performance. In this paper, the effects of CuO loading on Cu-Ce synergy in CuO/CeO2 nanorod catalysts and their performance in toluene combustion were systematically investigated. It was found that non-equilibrium plasma facilitated the dispersion of CuO active species on the CeO2 surface. With the increase of the CuO loading from 1 wt% to 4 wt%, the Cu-Ce synergistic effect was gradually improved, which generated Cu+/Cu2+ and Ce3+/Ce4+ redox electron pairs. The highest oxygen vacancy concentration and Cu+ content of CuCe-4 (4 wt%) resulting from strong Cu-Ce synergy accelerated the activation of chemisorbed oxygen and consequently improved the efficiency of toluene catalytic combustion.