A strategy to unlock the potential of CrN as a highly active oxygen reduction reaction catalyst
JOURNAL OF MATERIALS CHEMISTRY A(2020)
摘要
Developing cheap and highly active oxygen reduction reaction (ORR) electrocatalysts is of great importance for fuel cells and Zn-air batteries. Transition-metal nitrides are theoretically promising ORR catalysts, but their actual ORR performance is disappointing. Insufficient d electrons, low exposure of active sites and low conductivity are the three obstacles preventing transition-metal nitrides from being competitive ORR catalysts. Herein, we introduce a comprehensive solution that manages to remove all these obstacles and improve the ORR activity of transition-metal nitrides to the level of leading non-noble metal ORR catalysts. We first prepared a Cr/Z8C material by dispersing ZIF-8 derived carbon in an ethanol solution of CrCl3 followed by a nitridation process. Using the ZIF-8-derived carbon as a support, we managed to acquire very small CrN nanoparticles, overcoming their aggregation and enhancing their conductivity. By further doping with Fe or Co, we enriched the d electrons of CrN and enhanced its adsorption to oxygen. The Fe-doped Cr/Z8C material exhibited extraordinary ORR activity. Its ORR half-wave potential in alkaline media was 44 mV higher than that of the commercial Pt/C catalyst, and its ORR half-wave potential in acidic media was only 96 mV lower than that of the commercial Pt/C catalyst. This work demonstrates the great potential of transition-metal nitrides as ORR catalysts and opens up a new road to exploit cheap and highly active ORR catalysts.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要