Liu Jin-Cheng, Luo Feng, Li Jun
Center for Rare Earth and Inorganic Functional Materials, School of Materials Science and Engineering & National Institute for Advanced Materials, Nankai University, Tianjin 300350, China.
Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China.
J Am Chem Soc. 2023 Nov 22;145(46):25264-25273. doi: 10.1021/jacs.3c08697. Epub 2023 Nov 8.
Electronic structure is essential to understanding the catalytic mechanism of metal single-atom catalysts (SACs), especially under electrochemical conditions. This study delves into the nuanced modulation of "frontier orbitals" in SACs on nitrogen-doped graphene (N-C) substrates by electrochemical potentials. We observe shifts in Fermi level and changes of d-orbital occupation with alterations in electrochemical potentials, emphasizing a synergy between the discretized atomic orbitals of metals and the continuous bands of the N-C based environment. Using O and CO as model adsorbates, we highlight the direct consequences of these shifts on adsorption energies, unveiling an intriguing inversion of adsorption energies on Co/N-C SAC under negative electrochemical potentials. Such insights are attributed to the role of the d and d orbitals, pivotal for stabilizing the π* orbitals of O. Through this exploration, our work offers insights on the interplay between electronic structures and adsorption behaviors in SACs, paving the way for enhanced catalyst design strategies in electrochemical processes.
电子结构对于理解金属单原子催化剂（SACs）的催化机制至关重要，尤其是在电化学条件下。本研究深入探讨了电化学势对氮掺杂石墨烯（N-C）基底上SACs中“前沿轨道”的细微调制。我们观察到费米能级的移动以及随着电化学势的变化d轨道占据情况的改变，强调了金属离散原子轨道与基于N-C的连续能带之间的协同作用。使用O和CO作为模型吸附质，我们突出了这些移动对吸附能的直接影响，揭示了在负电化学势下Co/N-C SAC上吸附能的有趣反转。这些见解归因于d和d轨道的作用，它们对于稳定O的π*轨道至关重要。通过这项探索，我们的工作提供了关于SACs中电子结构与吸附行为之间相互作用的见解，为电化学过程中增强催化剂设计策略铺平了道路。
