In-based bimetallic catalysts show great potential to reduce CO₂ electrochemically. However, the nature of active sites and reaction mechanisms are not fully understood. This study systematically investigates the role of Cu in the Cu-In bimetallic catalysts during the reaction. The partial current densities of formate and CO show a linear correlation with increased Cu content. CuIn3 shows a total current density of 6.40 mA cm⁻² and the highest Faradic efficiency for C1 products of 99.3% at −0.7 V vs RHE. A series of characterizations reveal that the Cu¹⁺ species dope into the In(OH)₃ lattice for the Cu-In catalysts, while small CuO nanoparticles also form on the surface of catalyst with high Cu contents. The CuO and Cu¹⁺ species are reduced to metallic Cu⁰, leading to the formation of the Cu⁰-In(OH)₃ interfacial sites. Adding Cu is found to facilitate the adsorption of CO₂ and shift the rate-determining step for formate production.

In基双金属催化剂显示出电化学还原CO _{2的巨大潜力。}然而，活性位点的性质和反应机制尚不完全清楚。本研究系统地研究了Cu在反应过程中在Cu-In双金属催化剂中的作用。甲酸盐和 CO 的部分电流密度与增加的 Cu 含量呈线性相关。CuIn3 的总电流密度为 6.40 mA cm ^-2，C1 产品的最高法拉第效率在 -0.7 V vs RHE 时为 99.3%。一系列表征表明，Cu ¹⁺物质掺杂到 In(OH) _3中Cu-In 催化剂的晶格，同时在高 Cu 含量的催化剂表面也形成了小的 CuO 纳米颗粒。CuO和Cu ¹⁺物质被还原为金属Cu ⁰，导致Cu ⁰ -In(OH) ₃界面位点的形成。发现添加Cu有助于CO ₂的吸附并改变甲酸盐生产的速率决定步骤。