Enhanced effect of H<sub>2</sub> pretreatment on CuO<sub><italic>x</italic></sub>/CeO<sub>2</sub> catalyst for the CO plasma catalytic oxidation

Abstract

<p indent="0mm">The catalytic oxidation of carbon monoxide (CO) at low temperature has attracted more and more attention since it causes serious impacts on public health and the environment. Non-thermal plasma (NTP) has great potential to lower the temperature of catalytic oxidation of CO. In this study, CuO_{<italic>x</italic>}/CeO₂ catalyst was prepared by incipient wetness impregnation method and activated by H₂ reduction. The catalytic performances of CuO_{<italic>x</italic>}/CeO₂ catalysts before and after H₂ pretreatment in NTP catalytic system under different humidity conditions were compared, and the influences of H₂ pretreatment on the catalyst structure and the reaction mechanism were discussed. The results showed that H₂ pretreatment could improve the plasma catalytic activity of the CuO_{<italic>x</italic>}/CeO₂ catalysts and inhibit the emission of plasma-induced byproducts (O₃ and NO_{<italic>x</italic>}). Enhanced performance of plasma catalytic oxidation of CO over the H₂-pretreated CuO_{<italic>x</italic>}/CeO₂ catalysts was mainly ascribed to the increase of Cu⁺ active sites and oxygen vacancies on the catalyst surface. This study revealed the effect of H₂ pretreatment on the plasma catalytic oxidation of CO over the CuO_{<italic>x</italic>}/CeO₂ catalysts, which provided valuable information for the development of multifunctional catalysts in non-thermal plasma catalytic systems.