The electrocatalytic two-electron oxygen reduction reaction(2e^(-)ORR)for directly synthesizing H_(2)O_(2) solution is expected to replace the conventional anthraquinone method.Oxygen doped carbon materials are promis...The electrocatalytic two-electron oxygen reduction reaction(2e^(-)ORR)for directly synthesizing H_(2)O_(2) solution is expected to replace the conventional anthraquinone method.Oxygen doped carbon materials are promising as efficient electrocatalysts for the 2e^(-)ORR.Here,we developed a simple oxidation strategy to synthesize hydroxyl(-OH)and carboxyl(-COOH)co-modified carbon nanotubes(CNTs)for the 2e^(-)ORR.O-CNTs exhibit excellent H_(2)O_(2) electrosynthesis performance in alkaline media,achieving a superior H_(2)O_(2) yield(1.77 mol gcat^(-1) h^(-1) in an H-type cell).Meanwhile,the O-CNTs achieve more than 90% faradaic efficiency(FE)over a wide potential range of 0.2-0.6 V vs.RHE.In situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirms that O-CNTs could accelerate the generation of 2e^(-)ORR process intermediates(*OOH)for highly effective H_(2)O_(2) production.In addition,in a three-electrode flow cell,O-CNTs exhibit superior activity and selectivity compared to other metal-free carbon materials in an alkaline electrolyte.Furthermore,comparison experiments and density functional theory(DFT)calculations confirmed that the co-modification of oxygencontaining functional groups is the main source of activity and selectivity of the electrochemical 2e^(-)ORR.This strategy tunes 2e^(-)ORR reactive sites and provides insights into the design of carbon-based catalysts for H_(2)O_(2) electrosynthesis.展开更多
基金the Fundamental Research Funds for the Central Universities(202364004)the National Natural Science Foundation of China(No.22002146)the Foundation of the State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(Grant No.2018-k21,2021-K15).
文摘The electrocatalytic two-electron oxygen reduction reaction(2e^(-)ORR)for directly synthesizing H_(2)O_(2) solution is expected to replace the conventional anthraquinone method.Oxygen doped carbon materials are promising as efficient electrocatalysts for the 2e^(-)ORR.Here,we developed a simple oxidation strategy to synthesize hydroxyl(-OH)and carboxyl(-COOH)co-modified carbon nanotubes(CNTs)for the 2e^(-)ORR.O-CNTs exhibit excellent H_(2)O_(2) electrosynthesis performance in alkaline media,achieving a superior H_(2)O_(2) yield(1.77 mol gcat^(-1) h^(-1) in an H-type cell).Meanwhile,the O-CNTs achieve more than 90% faradaic efficiency(FE)over a wide potential range of 0.2-0.6 V vs.RHE.In situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirms that O-CNTs could accelerate the generation of 2e^(-)ORR process intermediates(*OOH)for highly effective H_(2)O_(2) production.In addition,in a three-electrode flow cell,O-CNTs exhibit superior activity and selectivity compared to other metal-free carbon materials in an alkaline electrolyte.Furthermore,comparison experiments and density functional theory(DFT)calculations confirmed that the co-modification of oxygencontaining functional groups is the main source of activity and selectivity of the electrochemical 2e^(-)ORR.This strategy tunes 2e^(-)ORR reactive sites and provides insights into the design of carbon-based catalysts for H_(2)O_(2) electrosynthesis.
