It is of vital importance to accelerate the sluggish oxygen reduction reaction (ORR) process at the cathode with earth-abundant metal-based catalysts for the commercialization of low-temperature polymer electrolyte membrane fuel cells. In consideration of high catalytic activity, long-term stability and low cost of potential ORR electrocatalysts, transition metal species have attracted much interest and transition metal-nitrogen-carbon (M−N/C, M = Fe, Co, Ni, Mn, etc.) catalysts have been widely considered as the most promising non-precious metal catalysts for ORR. Herein, the fundamental understanding of ORR catalytic mechanism and the identification of active centers are briefly introduced, and then different M−N/C catalysts classified by precursors with the strategies for design and optimization are highlighted. The challenges and possible opportunity for future development of high-performance ORR catalysts are finally proposed.

对于稀土聚合物电解质膜燃料电池的商业化，使用富含稀土的金属基催化剂加速阴极处缓慢的氧还原反应（ORR）过程至关重要。考虑到高活性，长期稳定性和潜在ORR电催化剂的低成本，过渡金属种类引起了人们的极大兴趣，过渡金属-氮-碳（M-N / C，M = Fe，Co，Ni，Mn，等）催化剂已被广泛认为是ORR最有前途的非贵金属催化剂。本文简要介绍了ORR催化机理的基本知识和活性中心的识别，然后重点介绍了前驱体分类的不同的M / N / C催化剂以及设计和优化策略。