CrN supported by carbon nanosheets as efficient catalysts toward oxygen reduction reaction and Zn‐air batteries
Yating Zhang, Fan Zhang, Zhe Lü, Junming Luo, Suyang Feng, Qi Wang, Hui Chen, Haoming Wu, Zhengpei Miao, Bin Chi, Neng Yu, Cheng-Hang You, Jing Li, Xinlong Tian
Abstract
Abstract Exploring non‐precious efficient oxygen reduction reaction (ORR) catalysts is of great significance to fuel cells and Zn‐air batteries (ZABs). CrN is a theoretically promising ORR catalyst, but its potential needs to be unlocked by proper supports that provide high conductivity and high exposure of active sites. In this work, we introduce a novel synthesis of carbon nanosheets‐supported CrN nanoparticles (CrN/C) by annealing the mixture of CrCl 3 , 1, 10‐phenanthroline and melamine via a two‐step pyrolysis. The prepared CrN/C materials show good ORR activity and stability in acidic and alkaline media. The optimal CrN/C material has an ORR half‐wave potential of 0.73 and 0.72 V (vs. reversible hydrogen electrode) in acidic and alkaline media, respectively. And it retains 82% and 78% of ORR current density in acidic and alkaline media after durability tests, respectively. Furthermore, the optimal CrN/C material‐based self‐breathing ZABs deliver a maximum power density of 168 mW·cm −2 , which is one of the highest among transition metal nitrides‐based ZABs. It is found that the ORR activity of CrN/C materials is highly related to the Cr–N valence state. This work highlights the good potential of CrN as robust ORR catalyst and verifies its promising application in ZABs.