Defect engineering of α-MnO2 catalyst for boosting the low-temperature toluene oxidation

In this paper, α-MnO₂–S, α-MnO₂–Ac, α-MnO₂–Cl and α-MnO₂–N have been prepared via redox reaction with potassium permanganate as oxidant, manganese acetate, manganese nitrate, manganese chloride and manganese sulfate as reducing agents to regulate the microstructure of α-MnO₂, and its catalytic oxidation performance of toluene was evaluated. Results showed that the α-MnO₂–Ac catalyst exhibited the highest catalytic activity (T₉₀ = 226 °C) for toluene oxidation. Compared with other Mn-based oxides, the α-MnO₂–Ac has more surficial oxygen vacancies and higher specific surface area, as well as excellent low temperature reduction performance, which is the reason on its remarkable activity for toluene oxidation. In addition, α-MnO₂–Ac catalyst presented good stability and repeatability during 50 h durability test under water vapor.