单原子催化剂电子结构调控实现高效多相催化

过去十年见证了单原子催化领域的快速发展，其最高的原子利用效率和充分暴露的活性位点使得单原子催化剂对众多反应的催化活性具有显著提升。在单原子催化领域的早期发展阶段，研究者只是关注单原子催化剂催化活性与催化选择性的提高，而其内在的反应机理以及活性位点同催化性能之间的构效关系往往被忽视。关于单原子催化剂中金属-基底相互作用的深入探讨能够帮助我们理解催化机理，并进一步指导多相催化剂的理性设计。值得注意的是，由于单原子催化剂均一的活性位点及其几何构型，我们可以通过理论计算以及一些原位的表征技术，来揭示其中的金属-基底相互作用，继而进一步促进单原子催化领域的发展以及多相催化剂的理性设计。这篇综述总结了金属-基底相互作用的基本概念，其作用，以及其在一些重要多相催化中的应用，最后提出了金属-基底相互作用在单原子催化领域所面临的挑战与机遇。

Enhancing Heterogeneous Catalysis by Electronic Property Regulation of Single Atom Catalysts

Past decades have witnessed the flourish of single atom catalysts (SACs) owing to their high atom-utilization efficiency and completely exposed active sites, which endows SACs with remarkably enhanced catalytic activities for various reactions. In the early development stage of SACs, researchers focus on the improvement of the catalytic performance of the catalysts, whereas the intrinsic catalytic reaction mechanism and the relationship between the electronic states of the metal sites and catalytic performance are usually ignored. Moreover, some sophisticated and complex structures, such as dual-atom SACs, heteroatomic doped SACs, SACs with precise second coordination shell, and other synergetic catalysts containing SACs, were fabricated recently. The insight into electronic metal-support interaction (EMSI) aids the understanding of the catalytic mechanism and thus serves as a guide for the fabrication of heterogeneous catalysts. Notably, the uniform active sites and characteristic local coordination configuration of SACs provide excellent platforms to study EMSI and bridge the gap between homogeneous and heterogeneous catalysts, which will contribute to the understanding of structure-performance relationships and enhance the development of SACs and rational design of heterogeneous catalysts. EMSI is especially important in heterogeneous catalysis. Through the rational design of the local coordination environment of SACs, the electronic structure of active sites can be accurately regulated, which will shift their d-band centers. This significantly alters the adsorption capability of intermediates and influences the final catalytic performance of the catalysts. With the development of advanced operando characterization techniques, the evolution of configuration, electronic properties, and local coordination environment could be revealed, thus providing researchers with a clear picture of the intrinsic mechanism of the catalytic system. In addition, with the aid of theoretical calculations, catalyst screening will be considerably more convenient, which will significantly reduce the number of aimless trials. After the optimal structure is determined, researchers should devise precise fabrication methods to realize the configuration. Herein, we initially introduce the basic principles and effects of EMSI. The stabilization, electronic property regulation, and electron transfer tunneling effects of EMSI are the foundation of SACs synthesis and catalytic mechanism elucidation, of which the former requires strong coordination stabilization energies while the latter focuses on the electronic state evolution of the active sites. Subsequently, EMSI applications in several important heterogeneous catalysis processes, such as selective hydrogenation, alcohol oxidation, water-gas shift reaction, and hydroformylation, are reviewed. Finally, the review discusses the challenges and future prospects for the future development of EMSI on SACs.