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

The development of non-noble metal-nitrogen ringcomplex(M-N-C) catalysts with high activity and stability forthe oxygen reduction reaction (ORR) is of great significance. However,M-N-C catalysts are generally prepared from precursorsunder high-temperature pyrolysis, which leads to complex product structuresand makes it difficult to identify the catalytic active center. Herein,we have successfully structured a novel bimetal phthalocyanine covalentorganic polymer/ordered mesoporous carbon (CoFe-COP/OMC) electrocatalystthrough a pyrolysis-free approach. Due to the well-defined activesites (Fe/CoN4), ordered COP structure, and highly conductivecarrier materials, the CoFe-COP/OMC nanocomposite exhibits remarkableORR electrocatalytic activity with a half-wave potential and initialpotential 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, theacquired hybrid catalysts show excellent methanol resistance and electrochemicalstability compared with Pt/C. The outstanding performance confirmsthat the CoFe-COP/OMC nanocomposite is a promising high-efficiencyORR catalyst for metal-air batteries and fuel cells.

Automated summary

The development of highly active and stable non-noble metal-nitrogen ringcomplex (M-N-C) catalysts for the oxygen reduction reaction (ORR) is important. However, M-N-C catalysts are typically prepared through high-temperature pyrolysis, resulting in complex product structures and difficulties in identifying the catalytic active center. In this study, a novel bimetal phthalocyanine covalent organic polymer/ordered mesoporous carbon (CoFe-COP/OMC) electrocatalyst was successfully synthesized using a pyrolysis-free approach. The CoFe-COP/OMC nanocomposite exhibited remarkable ORR electrocatalytic activity with excellent methanol resistance and electrochemical stability compared with Pt/C, making it a promising high-efficiency ORR catalyst for metal-air batteries and fuel cells.