Low-Temperature Removal Of Aromatics Pollutants Via Surface Labile Oxygen Over Mn-Based Mullite Catalyst Smmn2o5

The development of high efficient oxide catalyst is crucial to remove the aromatics pollutants. Herein, we propose a ternary mullite SmMn2O5 to catalytically oxidize benzene and toluene at a low temperature. Through a joint exploration of experimental characterizations and density functional theory calculations, the active species on the surface of the material are accessed. In the presence of the two-coordinated surface labile oxygen (O-lab), the hydrothermal-synthesized mullite achieves a remarkable deep oxidation performance with T-90 at 223 degrees C (benzene) and 228 degrees C (toluene), superior to most reported oxide catalysts. Simultaneously, SmMn2O5 displays no deactivation after 150 h reactions with repeating water vapor. Combining in situ DRIFTS and DFT calculations, the dissociation of maleic anhydride into acetic anhydride species on O-lab active sites turns out to be the rate-controlled step with a calculated kinetic barrier of 1.253 eV. These findings of O-lab allow to understand the catalytic oxidation of metal oxides at the atomic level and are thus imperative for the catalyst development.