Boosting Oxygen Reduction for High-Efficiency H₂ O₂ Electrosynthesis on Oxygen-Coordinated CoNC Catalysts

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Atomically dispersed cobalt-nitrogen-carbon (Co/NC) materials are key for selective H2O2 electrosynthesis via the two-electron oxygen reduction reaction (ORR).
• Existing Co/NC catalysts with CoN4 active sites show insufficient performance, necessitating improvements in atomic configuration.

Purpose of the Study:

• To develop and investigate a novel single-atom electrocatalyst (Co/NC) with a unique penta-coordinated Co/NC configuration (O/Co/N2C2).
• To optimize the atomic coordination of Co/NC for enhanced H2O2 selective electrosynthesis.

Main Methods:

• Synthesis of a single-atom electrocatalyst featuring a penta-coordinated Co/NC structure (O/Co/N2C2).
• Combination of theoretical predictions and experimental validation.
• Electrochemical evaluation in neutral solution to assess H2O2 selectivity and activity.

Main Results:

• The O/Co/N2C2 configuration uniquely modifies the cobalt center's charge state, optimizing adsorption of the *OOH intermediate.
• The synthesized Co/NC catalyst achieved over 90% selectivity for H2O2 production within a potential range of 0.36–0.8 V.
• A high turnover frequency of 11.48 s−1 was recorded, surpassing current state-of-the-art carbon-based catalysts.

Conclusions:

• The penta-coordinated Co/NC structure is highly effective for promoting the two-electron ORR pathway, favoring H2O2 electrosynthesis.
• This tailored atomic configuration offers a promising strategy for advancing high-performance electrocatalysts for H2O2 production.
• The developed Co/NC catalyst demonstrates superior performance compared to existing materials.