Effect of indium addition on the electrocatalytic performance of Zn–Al–Inx hydroxide for CO2 reduction to CO

Abstract

Due to the increasing content of carbon dioxide (CO₂) in the atmosphere and the greenhouse effect issue caused by the continuous carbon emissions, the conversion of CO₂ into carbon-containing clean energy has become a current research hotspot in the fields of chemistry and materials. In this study, five indium-added Zn–Al–In_x electrocatalysts were prepared via a hydrothermal synthesis method. The catalysts were characterized using analysis techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) to determine their composition, structure, elemental composition and oxidation states, surface microstructure, specific surface area, and pore size. Furthermore, the electrochemical performance of these catalysts in CO₂ reduction reaction (CO₂RR) was investigated. Research results have revealed that the addition level of indium has a significant impact on the electrocatalytic performance of the catalysts. Among them, the Zn–Al–In_0.2 hydroxide electrocatalyst with 0.2 mmol of indium addition exhibits excellent electrochemical performance in the electrocatalytic CO₂RR, particularly in the production of carbon monoxide (CO). The CO faradaic efficiency (CO FE) for CO₂ reduction to CO can reach up to 97.56% (−1.1 V vs. RHE), and its performance is maintained for at least 4.5 hours at −1.2 V vs. RHE.