Liu Tianyang, Xu Tianze, Li Tianchun, Jing Yu
Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
J Am Chem Soc. 2024 Aug 28;146(34):24133-24140. doi: 10.1021/jacs.4c08677. Epub 2024 Aug 14.
The two-electron CO reduction reaction (2e-CORR) is the most promising process for realizing industrial utilization of CO, but it is hindered by the competitive hydrogen evolution reaction (HER) because of the comparable equilibrium potential. Strategies to enhance 2e-CORR activity and selectivity by suppressing HER are highly demanded. Inspired by the low in-plane Young's modulus of the recently synthesized γ-graphyne (GY), we propose tensile-strain regulation as an effective method to improve the selectivity of the CORR against HER. By means of constant-potential calculations and constrained ab initio molecular dynamics simulations, we demonstrate the good stability and high CORR activity of GY-supported Co (Co-GY) single-atom catalysts (SACs). The change in potential of zero charges of *COOH is revealed to be more sensitive to tensile strain than that of *H species on Co-GY SACs, resulting in a slower change of its adsorption energy than that of *H species under working potentials and consequently enhanced CORR selectivity toward CO production. Besides, the strain-dependent regulation mechanism also applies to other M-GY SACs, demonstrating strain regulation as an effective strategy for designing and manipulating SACs for the selective 2e-CORR.
双电子CO还原反应（2e-CORR）是实现CO工业利用最具前景的过程，但由于平衡电位相近，受到竞争性析氢反应（HER）的阻碍。因此，迫切需要通过抑制HER来提高2e-CORR活性和选择性的策略。受最近合成的γ-石墨炔（GY）低面内杨氏模量的启发，我们提出拉伸应变调控作为提高CORR对HER选择性的有效方法。通过恒电位计算和受限从头算分子动力学模拟，我们证明了GY负载的Co（Co-GY）单原子催化剂（SACs）具有良好的稳定性和高CORR活性。结果表明，在Co-GY SACs上，COOH的零电荷电位变化对拉伸应变比H物种更敏感，导致其吸附能在工作电位下比*H物种变化更慢，从而提高了CORR对CO生成的选择性。此外，应变依赖的调控机制也适用于其他M-GY SACs，表明应变调控是设计和操纵用于选择性2e-CORR的SACs的有效策略。
