Boosting Oxygen Reduction for High‐Efficiency H2O2 Electrosynthesis on Oxygen‐Coordinated CoNC Catalysts

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2022-04, Vol.18 (17), p.n/a
• Main Authors: Shen, Hangjia, Qiu, Nianxiang, Yang, Liu, Guo, Xuyun, Zhang, Kun, Thomas, Tiju, Du, Shiyu, Zheng, Qifu, Attfield, J. Paul, Zhu, Ye, Yang, Minghui
• Format: Article
• Language: English
• Subjects: atomic coordinates; Atomic structure; Carbon; Catalysts; Chemical reduction; Co N C; Configurations; Electrocatalysts; high‐efficiency H 2O 2 electrosynthesis; Hydrogen peroxide; Nanotechnology; Nitrogen atoms; oxygen reduction; Oxygen reduction reactions; Selectivity
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202200730

Atomically dispersed CoNC is a promising material for H2O2 selective electrosynthesis via a two‐electron oxygen reduction reaction. However, the performance of typical CoNC materials with routine CoN4 active center is insufficient and needs to be improved further. This can be done by fine‐tuning its atomic coordination configuration. Here, a single‐atom electrocatalyst (Co/NC) is reported that comprises a specifically penta‐coordinated CoNC configuration (OCoN2C2) with Co center coordinated by two nitrogen atoms, two carbon atoms, and one oxygen atom. Using a combination of theoretical predictions and experiments, it is confirmed that the unique atomic structure slightly increases the charge state of the cobalt center. This optimizes the adsorption energy towards *OOH intermediate, and therefore favors the two‐electron ORR relevant for H2O2 electrosynthesis. In neutral solution, the as‐synthesized Co/NC exhibits a selectivity of over 90% over a potential ranging from 0.36 to 0.8 V, with a turnover frequency value of 11.48 s−1; thus outperforming the state‐of‐the‐art carbon‐based catalysts. The oxygen‐coordinated CoNC configuration (OCoN2C2) with a relatively electron‐deficient cobalt center, optimizes the adsorption energy towards *OOH intermediate, and therefore favors the two‐electron oxygen reduction reaction relevant for H2O2 electrosynthesis.