Electrocatalytic CO₂ reduction (ECR) represents a promising way for the utilization of renewable energy such as wind and solar to produce value-added fuels or chemicals. The process mainly suffers from the sluggish CO₂ reaction kinetics and the lack of efficient electrocatalysts. Herein, we investigated a wide range of transition metal (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Cd, Ir, Pt and Au) atoms anchored into monovacancy of antimonene (Sb monolayer) as single-atom catalysts (SACs) for ECR by first- principles calculation. Interestingly, non-precious TM atoms from the 3d group (TM = Sc, V, Cr, Mn, Fe, Co, Zn) supported on Sb monolayer show higher ECR selectivity than hydrogen evolution reaction selectivity. Moreover, the primary ECR product of these non-precious metal-based SACs is CH₄, except for Zn which produces HCOOH. Co@Sb monolayer exhibits the lowest overpotential 0.50 V, which is comparable to reported excellent electrocatalysts. The interaction between TM atom and Sb monolayer greatly affects the intrinsic activity of SACs. Meanwhile, the interaction between TM atoms and intermediates of the potential determining steps (PDS) will determine the overpotential and final products of ECR. This work opens a new family of stable and selective SACs based on antimonene monolayer and provides new insights for screening SACs by charge transfer of bonding atoms.

电催化 CO ₂还原 (ECR) 是利用风能和太阳能等可再生能源生产增值燃料或化学品的一种很有前景的方法。该过程的主要缺点是CO ₂反应动力学缓慢和缺乏有效的电催化剂。在此，我们研究了多种过渡金属（TM = Sc、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、Mo、Ru、Rh、Pd、Ag、Cd、Ir、Pt 和 Au ）原子锚定在锑烯（Sb 单层）的单空位中，作为 ECR 的单原子催化剂（SAC），通过第一性原理计算。有趣的是，来自 3 d 的非贵重 TM 原子支持在 Sb 单层上的基团 (TM = Sc, V, Cr, Mn, Fe, Co, Zn) 显示出比析氢反应选择性更高的 ECR 选择性。此外，这些非贵金属基 SAC 的主要 ECR 产物是 CH ₄，除了产生 HCOOH 的 Zn。Co@Sb 单层表现出最低的过电位 0.50 V，可与报道的优秀电催化剂相媲美。TM 原子​​和 Sb 单层之间的相互作用极大地影响了 SAC 的内在活性。同时，TM原子与电位决定步骤（PDS）的中间体之间的相互作用将决定ECR的过电位和最终产物。这项工作开辟了一个基于锑烯单层的稳定和选择性 SAC 的新家族，并为通过键合原子的电荷转移筛选 SAC 提供了新见解。