The electrochemical conversion of CO₂ to high-value molecules is an elegant alternative for combining CO₂ utilization with renewable energy conversion and storage. Herein we report the preparation and characterization of indium catalysts for the electrochemical CO₂ reduction to formate. Indium coatings were prepared by electrodeposition from a deep eutectic solvent (DES) comprising 1:2 molar choline chloride and ethylene glycol (12CE). The electrochemical behavior of indium chloride in this DES was investigated by cyclic voltammetry (CV) on copper, glassy carbon (GC) and platinum electrodes. The effect of InCl₃ concentration, electrolyte temperature and deposition method on the phase and morphology of the coatings were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Indium deposits on copper and carbon were deployed as catalysts for the CO₂ electrolysis in aqueous media. Chemical analysis by HPLC, GC, and NMR revealed an optimum efficiency toward formate at -1.9 V vs. Ag/AgCl. Indium coatings prepared by potentiostatic deposition showed faradaic efficiencies (FE) up to 72.5 %. Gas diffusion electrodes (GDE) coated with indium led to formate concentrations up to 76 mM and formation rates of 0.183 mmol cm^-2 h^-1, which was considerably superior to indium coatings on planar electrodes.

将CO ₂电化学转化为高价值分子是将CO _2的利用与可再生能源的转化和存储相结合的理想选择。本文中，我们报道了用于将CO ₂电化学还原为甲酸酯的铟催化剂的制备和表征。通过从包含1：2摩尔氯化胆碱和乙二醇（12CE）的深共熔溶剂（DES）中进行电沉积来制备铟涂层。通过循环伏安法（CV）在铜，玻璃碳（GC）和铂电极上研究了氯化铟在该DES中的电化学行为。InCl ₃的作用通过X射线衍射（XRD）和扫描电子显微镜（SEM）分析了涂层的浓度，电解质温度和沉积方法对涂层相和形貌的影响。铜和碳上的铟沉积物被用作在水性介质中进行CO ₂电解的催化剂。通过HPLC，GC和NMR进行的化学分析显示，相对于 Ag / AgCl，在-1.9 V时甲酸的最佳效率 。通过恒电位沉积制备的铟涂层显示高达72.5％的法拉第效率（FE）。涂有铟的气体扩散电极（GDE）导致甲酸盐浓度高达76 mM，形成速率为0.183 mmol cm ^-2  h ^-1，这大大优于平面电极上的铟涂层。