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

Abstract

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.