摘要
实现质子交换膜燃料电池(PEMFC)的商业化应用亟需开发出低成本的高效氧还原(ORR)电催化剂以替代昂贵的Pt基材料.过去十余年,研究人员对由M-Nx活性位点和富缺陷碳质基底组成的热解M-N-C基单原子催化剂进行了深入的研究,以期进一步提高催化剂的性能并降低成本.其中,Fe-N-C基单原子催化剂表现出了较好的催化性能和巨大的应用潜力.近年来人们发现,在单原子催化剂中引入另一种金属原子组成的双原子催化剂具有特殊的几何构型和电子结构,有利于反应过程中原子间相互作用,使催化性能进一步提高.其中,在Fe-N-C基催化剂中引入另一种金属原子组成的Fe-M-N-C双原子催化剂(M代表金属)可以进一步激发Fe-N-C催化剂的本征活性,相关研究也吸引了越来越多的关注.本文综述了Fe-M-N-C基双原子催化剂催化ORR过程的研究进展.首先,讨论了双原子催化剂催化ORR的机制,其中引入的第二种金属原子通过协同和/或调制效应发挥作用.其后,系统总结了Fe-M-N-C的合成方法、表征技术和计算方法,以进一步推动双原子催化剂的研究.再后,根据金属原子之间的相互作用,将双原子催化剂分为Marriage型和Conjunct型.最后,结合双原子位点的原子构型详细讨论了不同双原子催化剂的作用机制:包括提供额外催化位点、改变吸附构型、调节电子结构等.本文还对Fe-M-N-C基双原子催化剂面临的主要挑战和发展机遇进行了总结,并对未来的研究方向进行了展望.一些关键的发展方向应该得到充分的关注和发展,包括Fe基双原子位点的精准合成、双原子位点的可靠识别、对催化机理的深入认识、Fe基催化剂在酸性环境中的稳定性以及具有最佳活性的双原子位点构型.综上,本文对Fe-M-N-C基双原子催化剂研究现状进行了系统的总结,希望为未来理性设计催化剂提供一定的参考.
Fe-N-C based single-atom catalysts(SACs)with isolated Fe atoms dispersed on nitrogen-dopedcarbon matrix have achieved sustained attention for oxygen reduction reaction due to their greatpotential in replacing the Pt based noble catalysts in terms of catalytic activity.To further trigger theintrinsic activity of Fe-N-C,Fe based dual-atom catalysts(DACs,i.e.,Fe-M-N-C)have been intensivelystudied,which confer the catalysts with readily tunable geometric configurations,electronic structures,thereby tailored catalytic properties.In this review,current progress on the rational design ofFe-M-N-C based DACs for enhanced oxygen reduction catalysis is summarized.Firstly,the ORRmechanisms on DACs are discussed where the second metal atoms can function through synergisticeffect and/or modulation effect to promote the intrinsic catalytic activity.Moreover,the currentlyavailable synthetic approaches,characterization techniques and computational methods are systematicallyreviewed to aid the investigation of DACs.Then,DACs are classified into marriage-typeand conjunct-type based on the interaction between metal atoms,whose properties are discussed atlength with the atomic configuration.At last,the main challenges of Fe-M-N-C based DACs aresummarized and some appealing directions towards highly efficient and stable energy applicationsare provided for their further enhancement.
作者
樊哲琛
万浩
余浩
葛君杰
Zhechen Fan;Hao Wan;Hao Yu;Junjie Ge(School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,Anhui,China;Dalian National Laboratory for Clean Energy,Dalian 116023,Liaoning,China)
基金
国家重点研发计划(2022YFB4004100)
国家自然科学基金(U22A20396)
安徽省自然科学基金(2208085UD04)
中国科学院低碳转化科学与工程重点实验室开放课题资助项目(KLLCCSE-202202)
中国科学院洁净能源创新研究院合作基金(DNL202010).
关键词
氧还原反应
铁基催化剂
双原子催化剂
催化活性
原子构型
Oxygen reduction reaction
Fe based catalyst
Dual-atom catalyst
Catalytic activity
Atomic configuration
