Neutral H_(2)O_(2)electro synthesis via two-electron oxygen reduction reaction(2e^(-)-ORR)is a promising alternative to replace traditional anthraquinone processes.However,it still remains significantly challenging to...Neutral H_(2)O_(2)electro synthesis via two-electron oxygen reduction reaction(2e^(-)-ORR)is a promising alternative to replace traditional anthraquinone processes.However,it still remains significantly challenging to develop efficient electrocatalysts due to sluggish neutral2e^(-)-ORR kinetics.Herein,we reported abundant ultrafine Co/Co_(2)O_(3)nanoparticles(NPs)anchored oxidic nitrogendoped carbon nanotubes(Co/Co_(2)O_(3)@OCNT)derived from the pyrolysis of the mixed OCNT and Co@Tpy,presenting synergistical enhancement effect on the water dissociation to supply active hydrogen coupling with O_(2)to produce H_(2)O_(2)at positive onset potential of 0.66 V vs.RHE.As a result,Co/Co_(2)O_(3)@OCNT achieves a record current density of 4.0 mA cm^(-2)at 0.2 V vs.RHE and nearly 100%H_(2)O_(2)selectivity at the potential from 0 to 0.5 V vs.RHE.In situ observations demonstrated that ultrafine Ci/Co_(2)O_(3)NPs and nitrogen-doped carbon supports would synergistic ally improve the active hydrogen feeding further to facilitate the formation of key intermediate*OOH.Furthermore,based on the sandwiched configuration of the flow cell,Co/Co_(2)O_(3)@OCNT shows a superior performance with the yield rate of salt-free aqueous H_(2)O_(2)solution around63.4 mol gcat^(-1)h^(-1)at 200 mA cm^(-2)and the corresponding Faradaic efficiency of 85%.Moreover,integration of Co/Co_(2)O_(3)@OCNT into this cell achieves high real-time production concentration of H_(2)O_(2)around 20 mM at 200 mA cm^(-2)by varying the pure water flow rate to1 mL min-1,suggesting the huge potential of salt-free H_(2)O_(2)solution production.This work provides a novel strategy for developing efficient neutral electrocatalysts and feasible process of neutral H_(2)O_(2)production.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22466010)Guizhou Provincial Basic Research Program(Natural Science)(No.ZK[2023]47)+4 种基金key program(No.ZD[2025]075)the Innovation and Entrepreneurship Project for overseas Talents in Guizhou Province[2022]02Specific Natural Science Foundation of Guizhou University(No.X202207)the National Undergraduate Innovation and Entrepreneurship Training Program(Nos.gzugc2023006 and gzusc2024012)the SRT project of Guizhou University(No.2023SRT029)
文摘Neutral H_(2)O_(2)electro synthesis via two-electron oxygen reduction reaction(2e^(-)-ORR)is a promising alternative to replace traditional anthraquinone processes.However,it still remains significantly challenging to develop efficient electrocatalysts due to sluggish neutral2e^(-)-ORR kinetics.Herein,we reported abundant ultrafine Co/Co_(2)O_(3)nanoparticles(NPs)anchored oxidic nitrogendoped carbon nanotubes(Co/Co_(2)O_(3)@OCNT)derived from the pyrolysis of the mixed OCNT and Co@Tpy,presenting synergistical enhancement effect on the water dissociation to supply active hydrogen coupling with O_(2)to produce H_(2)O_(2)at positive onset potential of 0.66 V vs.RHE.As a result,Co/Co_(2)O_(3)@OCNT achieves a record current density of 4.0 mA cm^(-2)at 0.2 V vs.RHE and nearly 100%H_(2)O_(2)selectivity at the potential from 0 to 0.5 V vs.RHE.In situ observations demonstrated that ultrafine Ci/Co_(2)O_(3)NPs and nitrogen-doped carbon supports would synergistic ally improve the active hydrogen feeding further to facilitate the formation of key intermediate*OOH.Furthermore,based on the sandwiched configuration of the flow cell,Co/Co_(2)O_(3)@OCNT shows a superior performance with the yield rate of salt-free aqueous H_(2)O_(2)solution around63.4 mol gcat^(-1)h^(-1)at 200 mA cm^(-2)and the corresponding Faradaic efficiency of 85%.Moreover,integration of Co/Co_(2)O_(3)@OCNT into this cell achieves high real-time production concentration of H_(2)O_(2)around 20 mM at 200 mA cm^(-2)by varying the pure water flow rate to1 mL min-1,suggesting the huge potential of salt-free H_(2)O_(2)solution production.This work provides a novel strategy for developing efficient neutral electrocatalysts and feasible process of neutral H_(2)O_(2)production.
