Significantly Enhanced Oxygen Reduction Reaction Activity in Co-N-C Catalysts through Synergistic Boron Doping

Abstract

The weak adsorption energy of oxygen-containing intermediates on Co center leads to a considerable performance disparity between Co-N-C and costly Pt benchmark in catalyzing oxygen reduction reaction (ORR). In this work, we strategically engineer the active site structure of Co-N-C via B substitution, which is accomplished by the pyrolysis of ammonium borate. During this process, the in-situ generated NH₃ gas plays a critical role in creating surface defects and boron atoms substituting nitrogen atoms in the carbon structure. The well-designed CoB₁N₃ active site endows Co with higher charge density and stronger adsorption energy toward oxygen species, potentially accelerating ORR kinetics. As expected, the resulting Co-B/N-C catalyst exhibited superior ORR performance over Co-N-C counterpart, with 40 mV, and fivefold enhancement in half-wave potential and turnover frequency (TOF). More importantly, the excellent ORR performance could be translated into membrane electrode assembly (MEA) in a fuel cell test, delivering an impressive peak power density of 824 mW·cm^-2, which is currently the best among Co-based catalysts under the same conditions. This work not only demonstrates an effective method for designing advanced catalysts, but also affords a highly promising non-precious metal ORR electrocatalyst for fuel cell applications.

Keywords

Oxygen reduction reaction / Proton exchange membrane fuel cell / Single-atom catalyst / Co-N-C / Boron doping

Supporting Information

The authors have cited additional references within the Supporting Information [30,31]. ((Please include SI references with consecutive numbering directly after the last manuscript reference: 1, 2, 3, … 30, 31))

Acknowledgements

Authors wish to thank the National Key Research and Development Program of China (2022YFB4004100), National Natural Science Foundation of China (22272161, 22179126), the Jilin Province Science and Technology Development Program (YDZJ202202CXJD011, 20240101019JC), Jilin Province major science and technology project (222648GX0105103875) for financial supports. The Shanghai Synchrotron Radiation Facility for conducting the X-ray absorption spectroscopy experiments at BL11B station is greatly appreciated.

Conflicts of Interest

The authors declare no conflict of interests.

Data Availability

Data will be made available on request.

Author Contribution

Chang Lan: Conceptualization, Investigation, Writing - original draft, Formal analysis. Jing-Sen Bai: Investigation, Formal analysis. Xin Guan: Investigation. Shuo Wang: Formal analysis, Methodology. Nan-Shu Zhang: Investigation. Yu-Qing Cheng: Investigation. Jin-Jing Tao: Investigation. Yu-Yi Chu: Writing - review & editing. Mei-Ling Xiao: Writing - review & editing, Supervision. Chang-Peng Liu: Writing - review & editing, Supervision. Wei Xing: Writing - review & editing, Funding acquisition, Project administration.

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