In situ construction of MnO2 @CeO2 catalyst with a cake-like hierarchical nanosheets structure for efficient toluene oxidation

Cake-like MnO 2 @CeO 2 catalyst with hierarchical nanosheets structure has been successfully constructed by in situ methods. The relationship between structure and activity of the MnO 2 @CeO 2 catalyst was characterized using various analytical techniques. It is identified that rich surface oxygen species and better reducibility were generated due to the strong synergistic effect between MnO 2 and CeO 2 , and hence nearly T 90 toluene conversion can be obtained for the 10%-MnO 2 @CeO 2 catalyst under 240–300 °C. In addition, it is found that after loading MnO 2 on the multi-layer CeO 2 support to form a hierarchical cake-like structure, the oxygen vacancies, Ce 3+ /Ce 4+ and BET surface area of MnO 2 @CeO 2 increased significantly, which is beneficial to toluene adsorption and reaction. Furthermore, the in situ DRIFTS study demonstrated that the lattice oxygen and surface oxygen both participate in the toluene oxidation , whereas surface active oxygens adsorbed on the oxygen vacancies will lead to deep oxidation by forming abundance intermediates.