Exploring the role of oxygen species on β- and γ-MnO2 catalyst under in-plasma catalysis configuration at different temperature in CO oxidation using operando TPR-DRIFTS-MS

Catalyst surface active oxygen species have an important influence on plasma catalytic oxidation . However, the reaction process of CO and O 3 migration and transformation on the catalyst surface during discharge at different temperature is still unclear. In this study, β- and γ -MnO 2 are selected to unveil the roles of different oxygen species under in-plasma catalysis configuration at different temperature in CO oxidation. Operando TPR-DRIFTS-MS is used to reveal CO and O 3 oxidation pathways. The results show that O 3 can react with CO at room temperature, and O 3 is also converted to other reactive oxygen species on the catalyst surface. As the temperature increases, the oxygen species of the catalyst itself (Mn O and Mn-O-Mn) can react with CO to form oxygen vacancies (Mn-□-Mn and Mn=□). Mn-□-Mn are beneficial for O 2 decomposition and promotes the regeneration of Mn O and Mn-O-Mn. The carbonate covered on the surface of the catalyst is the rate-determining step of CO oxidation. It is hoped that Mn-based catalysts with more reactive oxygen species and oxygen defects will be prepared to facilitate low-temperature CO oxidation under plasma conditions.