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.

Automated summary

The ternary mullite SmMn2O5 has been successfully developed as a high-efficient oxide catalyst for benzene and toluene oxidation at low temperatures through a combination of experimental characterizations and density functional theory calculations. This catalyst shows remarkable deep oxidation performance and good stability, making it superior to most reported oxide catalysts. The discovery of the active oxygen species on the surface of the material provides crucial insights for understanding the catalytic oxidation of metal oxides at the atomic level.