Electrocatalysis is considered to be an effective method for carbon dioxide (CO₂) reduction to formate (HCOOH) and achieving renewable energy conversion. Unfortunately, limited by the high overpotential, low selectivity, and poor stability of the existing catalysts, the electrocatalytic CO₂ reduction (CO₂RR) is far from practical application. Herein, we designed a series of Cu_xSn_y (x, y are the molar ratio) bimetallic alloy catalysts by the co-electrodeposition strategy for electrocatalytic CO₂RR to HCOOH generation. Bimetallic Cu_xSn_y catalysts are found to be more efficient than their monometal counterparts because of metal synergistic effects. In more detail, the Cu₁Sn₃-CC catalyst delivers high selectivity for HCOOH evolution of above 85% over a wide potential range (−0.8 V to −1.0 V vs. reversible hydrogen electrode [RHE]) with a low onset potential of −0.6 V vs. RHE and exhibits a Faradaic efficiency of 91.38% toward HCOOH generation and a maximum current density of 13.79 mA/cm² at −0.8V vs. RHE. Furthermore, after long-term (36 h) operation, the Faraday efficiency of the catalyst is still higher than 88.35%. This work paves a facile way to synthesize novel bimetallic electrocatalysts for efficient production of HCOOH.

电催化被认为是将二氧化碳（CO ₂）还原为甲酸盐（HCOOH）并实现可再生能源转化的有效方法。遗憾的是，受现有催化剂过电位高、选择性低和稳定性差的限制，电催化CO ₂还原（CO ₂ RR）远未实际应用。在此，我们通过共电沉积策略设计了一系列 Cu _x Sn _y ( x , y是摩尔比) 双金属合金催化剂，用于电催化 CO ₂ RR 生成 HCOOH。双金属Cu _x Sn _y由于金属协同效应，发现催化剂比它们的单金属对应物更有效。更详细地说，Cu ₁ Sn ₃ -CC 催化剂在较宽的电位范围内（-0.8 V 至 -1.0 V 与可逆氢电极 [RHE]）对 HCOOH 析出的选择性高于 85%，且起始电位为-0.6 V vs. RHE 并且 在-0.8V vs. RHE 下表现出 91.38% 的法拉第效率对 HCOOH 生成和 13.79 mA/cm ²的最大电流密度。此外，在长期（36 h）运行后，催化剂的法拉第效率仍高于88.35%。这项工作为合成新型双金属电催化剂以有效生产 HCOOH 铺平了道路。