Self-templated nitrogen-doped mesoporous carbon decorated with double transition-metal active sites for enhanced oxygen electrode catalysis

Meng-Fei Qiao¹，Ying Wang¹，Lei Li²，Guang-Zhi Hu^1,2，Guo-An Zou¹，Xamxikamar Mamat¹，Ye-Min Dong³，Xun Hu⁴

1. Key Laboratory of Chemistry of Plant Resources in Arid Regions, Xinjiang Technical Institute of Physics and Chemistry,Chinese Academy of Science2. College of Biological, Chemical Sciences and Engineering,Jiaxing University3. State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences4. School of Material Science and Engineering, University of Jinan

摘 要：The development of high-performance,low-cost bifunctional catalysts with long-term stability for the oxygen reduction reaction（ORR）and oxygen evolution reaction（OER）is one of the most critical challenges for the large-scale application of metal–air batteries.Herein,we report an advanced nitrogen-doped mesoporous carbon（NMC）composite（NiCo₂O₄/CoN_x–NMC）formed from a mixture of Co-and Ni-hydroxide-infiltrated phenolic resin and melamine resin.This composite exhibits superior electrocatalytic activity,stability,and selectivity for the ORR and OER.The activity parameter（DE）,which is an indicator of the overall catalytic activity of bifunctional catalysts,was 0.76 V for NiCo₂O₄/CoN_x–NMC.Therefore,catalyst outperforms the majority of previously reported non-precious metal-based bifunctional electrocatalysts.The remarkable ultra-high catalytic performance of NiCo₂O₄/CoN_x–NMC for the ORR and OER can be attributed to the presence of different active sites of the CoN_x structure and the formation of NiCo₂O₄ with the spinel structure,which was obtained by a stepwise pyrolysis process.This synthesis strategy opens a new avenue for the rational design of highly active bifunctional electrocatalysts.

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