Catalytic absorption pathway with kinetically favorable dissolution of nitric oxide in aqueous absorbents

Abstract

AbstractNitrogen capture is a crucial strategy for coping with the environmental crisis arising from continually industrial NO emissions, while it suffers from the generally inefficient aquatic absorbent. This work developed a novel absorbent with favorable gas affinity via using sterically hindered imidazole to regulate the gas–liquid interface of typical K2S2O8 solution, initially achieving an efficiently catalytic absorption of poorly soluble NO. The best catalytic absorption efficiencies increased from 17.83% to 91.90% as compared to traditional one. Moreover, an established absorption kinetic model indicated that both capacity and rate of NO dissolution were increased. The imidazole molecules spontaneously migrated to gas–liquid interface of solution and imparted an additional dissolution impetus to NO. This catalytic absorption method overcoming the conventional NO dissolution limitation in water not only improves commercial NO capture, but also provides a new design of aquatic absorbent for heterogeneous reactions requiring transporting poorly soluble gases in aqueous solvents.