Formate is an important liquid chemical, which can be produced by electrocatalytic carbon dioxide reduction reaction (CO₂RR). Most of the metal catalysts for CO₂RR to formate are toxic or noble metals, such as Cd, Hg, Pb, Sn and Pd, leading to the environmental pollution or increased production costs. Herein, we develop an environmentally friendly and low-cost NiZn alloy catalyst for CO₂RR to formate. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) confirm the alloy structure of the prepared NiZn catalyst. As for a catalyst for CO₂RR, the NiZn alloy exhibits the FE_HCOO^- (Faraday efficiency of HCOO^-) of 36 ± 0.7% at −0.9 V vs. RHE in 0.1 M KHCO₃, and remarkable stability for 40,000 s at −0.8, −0.9, −1.0 and −1.1 V vs. RHE, respectively. Theoretical calculation results indicate that the NiZn alloy exhibits the middle valence electron structure between the Zn and Ni metal, resulting in the favorable pathway for HCOOH formation but unfavorable for the hydrogen evolution reaction and CO production. The Ultraviolet Photoelectron Spectroscopy results verify the modulated valence electron structure for NiZn alloy as compared to Ni and Zn, consistent with the theoretical calculation results. This work provides new insights into design of alloy catalysts for CO₂RR to formate.

甲酸盐是一种重要的液体化学品，可通过电催化二氧化碳还原反应（CO ₂ RR）产生。CO ₂ RR形成甲酸的金属催化剂大多是有毒或贵金属，如Cd、Hg、Pb、Sn和Pd，导致环境污染或增加生产成本。在此，我们开发了一种环保、低成本的 NiZn 合金催化剂，用于 CO ₂ RR 的甲酸盐化。X 射线衍射 (XRD)、X 射线光电子能谱 (XPS) 和透射电子显微镜 (TEM) 证实了制备的 NiZn 催化剂的合金结构。对于 CO ₂ RR的催化剂，NiZn 合金表现出 FE _HCOO ^-（_{HCOO 的}法拉第效率^-) 36 ± 0.7% 在 -0.9 V 与 RHE 的 0.1 M KHCO _{3 中}，以及在 -0.8、-0.9、-1.0 和 -1.1 V 与 RHE 下分别保持 40,000 秒的显着稳定性。理论计算结果表明，NiZn合金表现出介于Zn和Ni金属之间的中间价电子结构，有利于HCOOH的形成，但不利于析氢反应和CO的产生。紫外光电子能谱结果验证了 NiZn 合金与 Ni 和 Zn 相比的调制价电子结构，与理论计算结果一致。这项工作为设计用于 CO ₂ RR 甲酸化的合金催化剂提供了新的见解。