Pyrolysis-Free Synthesis of Bimetal Phthalocyanine Covalent Organic Polymers/Ordered Mesoporous Carbon Nanocomposites for an Efficient Oxygen Reduction Reaction

• Published in: ACS applied nano materials 2023-07, Vol.6 (13), p.11252-11259
• Main Authors: Mo, Yiping, Liu, Guilin, Liu, Shanshan, Lu, Wangyang
• Format: Article
• Language: English
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.3c01276

The development of non-noble metal–nitrogen ring complex (M–N–C) catalysts with high activity and stability for the oxygen reduction reaction (ORR) is of great significance. However, M–N–C catalysts are generally prepared from precursors under high-temperature pyrolysis, which leads to complex product structures and makes it difficult to identify the catalytic active center. Herein, we have successfully structured a novel bimetal phthalocyanine covalent organic polymer/ordered mesoporous carbon (CoFe-COP/OMC) electrocatalyst through a pyrolysis-free approach. Due to the well-defined active sites (Fe/CoN4), ordered COP structure, and highly conductive carrier materials, the CoFe-COP/OMC nanocomposite exhibits remarkable ORR electrocatalytic activity with a half-wave potential and initial potential of 0.908 and 0.932 V (vs reversible hydrogen electrode (RHE)), respectively, a limiting current density of 5.35 mA cm–2, and a nearly four-electron reduction pathway. In addition, the acquired hybrid catalysts show excellent methanol resistance and electrochemical stability compared with Pt/C. The outstanding performance confirms that the CoFe-COP/OMC nanocomposite is a promising high-efficiency ORR catalyst for metal–air batteries and fuel cells.