Comparison between hydrothermal and a facile sonochemical synthesis of Mn1-XCeXOY, at different Ce loading, towards the catalytic oxidation of toluene

摘要

Volatile organic compounds (VOCs) are harmful to human health due to their carcinogenicity and toxicity. In addition, they are responsible for the generation of secondary atmospheric pollutants. Catalytic oxidation is an effective alternative for the reduction of these types of emissions. In this context, Ce-Mn oxides have been reported as excellent catalyst because of their low cost, redox capacity, and oxygen mobility. To date, the best Ce-Mn oxide catalysts have been produced using hydrothermal synthesis. In the present work, we propose a novel, facile, environmental-friendly, and low-cost sonochemical method for the synthesis of Mn-Ce oxides with different Ce loadings. The new materials were characterized, and catalytic activity was measured in toluene oxidation reactions. Results demonstrated that, despite the low surface area of Mn-Ce oxides prepared by sonochemical method, these samples showed a superior catalytic activity with T-90 values of 266 degrees C. This performance was the result of the higher Mn4+ content, as well as improved reducibility and activation of O-lat species as compared to that of hydrothermally synthesized catalysts. However, the interaction between Mn2O3 and MnO2 in the hydrothermally synthesized catalysts resulted in a greater stability in long-term oxidation reactions.