Specific roles of lattice oxygen and asymmetric interface Cu-[Ox]-Ce structure-relating chemisorbed oxygen over CuO/CeO2 on the catalysis of benzene combustion

Abstract

Copper-ceria catalysts exhibit high prospects in the catalysis of VOCs combustion, during which lattice oxygen and chemisorbed oxygen species play indispensable roles. However, understanding their specific operating mechanisms still remains a challenge. Shaped CeO2 and CuO/CeO2 counterparts were synthesized for benzene catalytic combustion. Pure CeO2, especially for nanorod-CeO2, possessed high low-temperature activity (LTA) due to numerous active lattice oxygen following the initial step of Mars-van Krevelen mechanism. Conversely, the impaired LTA (15–40 °C upshift at 15 % conversion) but improved high-temperature activity (HTA) were obtained by varying surface local environment upon CuO loading. 5 wt% CuO/nanoparticle-CeO2 exhibited the highest mobile chemisorbed oxygen relating to the strong oxygen transfer capacity of asymmetric interface Cu-[Ox]-Ce structures affected by ceria crystal planes and sizes was verified by density functional theory calculations and experiments, despite the strong CuO-CeO2 synergistic effects. This study provides a promising direction for engineering benzene degradation catalysts with excellent low-temperature performance.