Facile preparation of amorphous CenMnOx catalysts and their good catalytic performance for soot combustion

Abstract

Diesel engines are widely used because of their low fuel consumption, high fuel efficiency, high reliability, and safety. However, the soot particles contained in diesel engine exhaust have become one of the main sources of urban haze, and their elimination has great significance for environmental protection and economics. In the present study, a series of CenMnOx catalysts with different Ce contents and calcination temperatures were successfully synthetized via a simple hydrothermal process, and the physicochemical characteristics of the as-prepared catalysts were investigated. That CenMnOx composite oxides were amorphous, contradicting previous reports that manganese and cerium usually form MnxCe1-xOδ with crystalline structures. Due to Ce doping, the amorphous Ce1MnOx catalysts have higher specific surface area, greater porosity, and better ability to activate oxygen species than pure MnOx catalysts. The amorphous catalysts also exhibit good stability, sulfur and water resistance for catalytic combustion of soot particles. Among the prepared catalysts, Ce1MnOx calcinated at 450 °C has the best catalytic activity, the values of T10, T50 and T90 were 258 °C, 327 °C and 370 °C, respectively. Based on their simple preparation, low cost, and good catalytic performance, the amorphous CenMnOx catalysts show promise for application in soot combustion.