A new strategy for plasma-catalytic reduction of NO to N2 on the surface of modified Bi2MoO6

Abstract

Rational design of ingenious catalysts in plasma-catalysis system for NO reduction at room temperature in the presence of O2 is a major challenge. In this work, amino (NHx) groups and oxygen vacancies (OVs) decorated Bi2MoO6 (NHOv-BMO) was designed to reduce NO to N2 by density functional theory (DFT) in the first place. An “anchoring (NH3/He plasma)-reduction (O2/N2 plasma)” plasma-catalytic circular system was developed to simultaneously realize the construction of the special catalysts and then apply to NO elimination. Experimental results indicated that the adsorption and activation of NOx, the activation of catalysts in plasma, and the plasma discharge intensity were improved attributed to the NH3-plasma modification process. NO was firstly oxidized to NO2 by plasma, then NO2 experienced part-disproportionation reactions during adsorption on OVs, producing NO, N2O, N2 and nitrates. After activation of the catalysts, the adsorbed NOx was partly oxidized to nitrates by ·O2– on OVs sites via plasma motivated “pseudo photocatalysis”, then those adsorbed NOx, nitrates and the gaseous NO/NO2 were further reduced to N2 by NHx groups for NHOv-BMO. Possible reaction pathways and mechanisms were clarified. The special circular plasma-catalytic system for NO reduction and the way of theory guiding practice may inspire novel approaches toward the design of artful catalysts for targeted reactions.