Kim Jaehyun, Choi Sungkyun, Cho Jinhyuk, Kim Soo Young, Jang Ho Won
Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea.
Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
ACS Mater Au. 2021 Oct 25;2(1):1-20. doi: 10.1021/acsmaterialsau.1c00041. eCollection 2022 Jan 12.
Single-atom catalysts (SACs) have recently emerged as the ultimate solution for overcoming the limitations of traditional catalysts by bridging the gap between homogeneous and heterogeneous catalysts. Atomically dispersed identical active sites enable a maximal atom utilization efficiency, high activity, and selectivity toward the wide range of electrochemical reactions, superior structural robustness, and stability over nanoparticles due to strong atomic covalent bonding with supports. Mononuclear active sites of SACs can be further adjusted by engineering with multicomponent elements, such as introducing dual-metal active sites or additional neighbor atoms, and SACs can be regarded as multicomponent SACs if the surroundings of the active sites or the active sites themselves consist of multiple atomic elements. Multicomponent engineering offers an increased combinational diversity in SACs and unprecedented routes to exceed the theoretical catalytic performance limitations imposed by single-component scaling relationships for adsorption and transition state energies of reactions. The precisely designed structures of multicomponent SACs are expected to be responsible for the synergistic optimization of the overall electrocatalytic performance by beneficially modulating the electronic structure, the nature of orbital filling, the binding energy of reaction intermediates, the reaction pathways, and the local structural transformations. This Review demonstrates these synergistic effects of multicomponent SACs by highlighting representative breakthroughs on electrochemical conversion reactions, which might mitigate the global energy crisis of high dependency on fossil fuels. General synthesis methods and characterization techniques for SACs are also introduced. Then, the perspective on challenges and future directions in the research of SACs is briefly summarized. We believe that careful tailoring of multicomponent active sites is one of the most promising approaches to unleash the full potential of SACs and reach the superior catalytic activity, selectivity, and stability at the same time, which makes SACs promising candidates for electrocatalysts in various energy conversion reactions.
单原子催化剂（SACs）最近已成为克服传统催化剂局限性的最终解决方案，它弥合了均相催化剂和多相催化剂之间的差距。原子分散的相同活性位点可实现最大的原子利用效率、高活性以及对广泛电化学反应的选择性，由于与载体形成强原子共价键，其结构稳健性和稳定性优于纳米颗粒。通过多组分元素工程，SACs的单核活性位点可进一步调节，例如引入双金属活性位点或额外的相邻原子，如果活性位点的周围环境或活性位点本身由多种原子元素组成，那么SACs可被视为多组分SACs。多组分工程增加了SACs的组合多样性，并提供了前所未有的途径来突破单一组分比例关系对反应吸附和过渡态能量所施加的理论催化性能限制。多组分SACs精确设计的结构有望通过有益地调节电子结构、轨道填充性质、反应中间体的结合能、反应途径和局部结构转变，对整体电催化性能进行协同优化。本综述通过突出电化学转化反应方面的代表性突破来展示多组分SACs的这些协同效应，这可能缓解对化石燃料高度依赖的全球能源危机。还介绍了SACs的一般合成方法和表征技术。然后，简要总结了SACs研究中面临的挑战和未来方向。我们相信，精心定制多组分活性位点是释放SACs全部潜力并同时实现卓越催化活性、选择性和稳定性的最有前景的方法之一，这使SACs成为各种能量转换反应中电催化剂的有前途的候选者。
