Electrochemical oxygen reduction reaction(ORR)for preparing hydrogen peroxide(H_(2)O_(2))is a promising way to replace the anthraquinone method.The key to H_(2)O_(2)production is the development of catalysts to regula...Electrochemical oxygen reduction reaction(ORR)for preparing hydrogen peroxide(H_(2)O_(2))is a promising way to replace the anthraquinone method.The key to H_(2)O_(2)production is the development of catalysts to regulate the oxygen reduction reaction pathway.Here,nitrogen-doped Nb_(2)CT_(x)was prepared by NH3 annealing method.Compared with precursor Nb_(2)AlC(67.01%)and pure Nb_(2)CT_(x)(75.70%),nitrogen-doped Nb_(2)CT_(x)exhibited excellent performance for 2e−ORR with>90%H_(2)O_(2)selectivity(at 0.4 V vs.reversible hydrogen electrode(RHE)).Faradic efficiency of nitrogen-doped Nb_(2)CT_(x)reached 80.75%,whereas those for Nb2AlC and Nb_(2)CT_(x)were 60.35%and 39.27%,respectively.A desirable catalytic stability for 50 h was observed.Density functional theory(DFT)calculations indicated excellent activity of the nitrogen-doped Nb_(2)CT_(x)was attributed to the introduction of N.This excellent activity was conducive to the adsorption of oxygen and promoted the formation of the OOH intermediate.This work can serve as an important reference for regulating the electronic structure of MXene to expand the application area in the electrochemical field.展开更多
基金the National Key R&D Program of China(No.2021YFA1500900)the National Natural Science Foundation of China(Nos.22141001 and U21A20298).
文摘Electrochemical oxygen reduction reaction(ORR)for preparing hydrogen peroxide(H_(2)O_(2))is a promising way to replace the anthraquinone method.The key to H_(2)O_(2)production is the development of catalysts to regulate the oxygen reduction reaction pathway.Here,nitrogen-doped Nb_(2)CT_(x)was prepared by NH3 annealing method.Compared with precursor Nb_(2)AlC(67.01%)and pure Nb_(2)CT_(x)(75.70%),nitrogen-doped Nb_(2)CT_(x)exhibited excellent performance for 2e−ORR with>90%H_(2)O_(2)selectivity(at 0.4 V vs.reversible hydrogen electrode(RHE)).Faradic efficiency of nitrogen-doped Nb_(2)CT_(x)reached 80.75%,whereas those for Nb2AlC and Nb_(2)CT_(x)were 60.35%and 39.27%,respectively.A desirable catalytic stability for 50 h was observed.Density functional theory(DFT)calculations indicated excellent activity of the nitrogen-doped Nb_(2)CT_(x)was attributed to the introduction of N.This excellent activity was conducive to the adsorption of oxygen and promoted the formation of the OOH intermediate.This work can serve as an important reference for regulating the electronic structure of MXene to expand the application area in the electrochemical field.
