Interfacial Charging-Decharging Strategy for Efficient and Selective Aerobic NO Oxidation on Oxygen Vacancy

Intelligent defect engineering to harness surface molecular processes is at the core of selective oxidation catalysis. Here, we demonstrate that the two-electron-trapped oxygen vacancy (V-O) of BiOCL, a prototypical F center (V-O('')) is a superb site to confine O-2 toward efficient and selective NO oxidation to nitrate. Stimulated by solar light, V-O('') accomplishes NO oxidation through a two-electron charging (V-O('') + O-2 -> V-O('') -O-2(2-)) and subsequent one-electron decharging process (V-O('')-O-2(2)- + NO -> V-O-NO3- + e(-)). The back-donated electron is retrapped by V-O to produce a new single-electron-trapped V-O (V-O(')), simultaneously triggering a second round of NO oxidation (V-O' -O-2 + NO -> VO-NO3-). This unprecedented interfacial charging-decharging scheme alters the peroxide-associated NO oxidation selectivity from NO2 to NO3- with a high efficiency and thus hold great promise for the treatment of risky NOx species in indoor air.