Synthesis of MnOx from pectin-driven sol-gel route for catalytic oxidation of toluene

Abstract

A novel green pectin-driven sol-gel with an auto-combustion route was successfully applied for the synthesis of manganese oxide catalysts, which exhibited superior catalytic performance for low-temperature combustion of toluene compared to those cases using manganese oxide catalysts synthesized by traditional citric acid and glycine-driven sol-gel routes. The characterization results showed that the MnO_x-P catalyst synthesized by the present method exhibited a unique hierarchical mesoporous structure with lower crystallinity and smaller grain size, leading to abundant active species and defect structures. Comparing with the catalysts synthesized by those traditional sol-gel methods, the MnO_x-P catalyst had excellent low-temperature reducible performance and better oxygen mobility, which is considered to be resulted from the specific interaction of chelation and calcination processes. In addition, the MnO_x-P catalyst exhibited satisfactory long-term stability and water tolerance during catalytic toluene combustion process.