Surface oxygen vacancy-dependent molecular oxygen activation for propane combustion over α-MnO₂

Oxygen vacancies (O_V), as the sites of molecular oxygen adsorption and activation, play an important role in the catalytic combustion process of volatile organic compounds (VOCs). Revealing the relationship between O_V concentration and molecular oxygen activation behavior is of significance to construct the efficient catalysts. Herein, α-MnO₂ with different O_V concentrations was prepared to investigate the molecular oxygen activation for C₃H₈ combustion. It is disclosed that the enhanced O_V concentration in α-MnO₂ induced the reconfiguration of surface metal atoms, resulting in the transformation of oxygen activation configuration from end-on mode to side-on mode. Oxygen molecules in side-on mode possessed more localized electron density and weaker coordination bond strength with surrounding Mn atoms, which were more favorable to adsorb C₃H₈ molecules and activate C-H bond for the improved combustion performance. This work provides a new understanding to reveal that the increased O_V concentration contributes to more efficient VOCs combustion.