Zhao Shutao, Tang Xiao, Li Jingli, Zhang Jing, Yuan Di, Ma Dongwei, Ju Lin
Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutes, School of Physics and Electronic Science, Fuyang Normal University, Fuyang 236037, China.
College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing 210037, China.
Nanomaterials (Basel). 2022 Aug 15;12(16):2793. doi: 10.3390/nano12162793.
In the areas of catalysis and renewable energy conversion, the development of active and stable electrocatalysts continues to be a highly desirable and crucial aim. Single-atom catalysts (SACs) provide isolated active sites, high selectivity, and ease of separation from reaction systems, becoming a rapidly evolving research field. Unfortunately, the real roles and key factors of the supports that govern the catalytic properties of SACs remain uncertain. Herein, by means of the density functional theory calculations, in the Au/WSSe SAC, built by filling the single Au atom at the S vacancy site in WSSe monolayer, we find that the powerful binding between the single Au atom and the support is induced by the Au and W orbital hybridization, which is caused by the electron transfer between them. The extra tensile strain could further stabilize the Au/WSSe by raising the transfer electron and enhancing the orbital hybridization. Moreover, by dint of regulating the antibonding strength between the single Au atom and H atom, the extra tensile strain is capable of changing the electric-catalytic hydrogen evolution reaction (HER) performance of Au/WSSe as well. Remarkably, under the 1% tensile strain, the reaction barrier (0.06 eV) is only one third of that of free state. This theoretical work not only reveals the bonding between atomic sites and supports, but also opens an avenue to improve the electric-catalytic performance of SACs by adjusting the bonding with outer factors.
在催化和可再生能源转换领域，开发活性和稳定的电催化剂仍然是一个非常理想且至关重要的目标。单原子催化剂（SACs）提供孤立的活性位点、高选择性以及易于从反应体系中分离，成为一个快速发展的研究领域。不幸的是，支撑体在控制SACs催化性能方面的实际作用和关键因素仍不明确。在此，通过密度泛函理论计算，在通过在WSSe单层的S空位处填充单个Au原子构建的Au/WSSe SAC中，我们发现单个Au原子与支撑体之间的强结合是由Au和W的轨道杂化引起的，这是由它们之间的电子转移导致的。额外的拉伸应变可以通过提高转移电子和增强轨道杂化进一步稳定Au/WSSe。此外，通过调节单个Au原子与H原子之间的反键强度，额外的拉伸应变也能够改变Au/WSSe的电催化析氢反应（HER）性能。值得注意的是，在1%的拉伸应变下，反应势垒（0.06 eV）仅为自由态的三分之一。这项理论工作不仅揭示了原子位点与支撑体之间的键合，还开辟了一条通过调整与外部因素的键合来提高SACs电催化性能的途径。
