Controlled cerium doping in In₂O₃ derived from an In-MOF to boost electrocatalytic CO₂ reduction for selective formate production

Utilizing electrocatalytic technology to convert CO₂ into value-added carbon products contributes to establishing a carbon-neutral cycle and alleviating environmental pressure. However, developing electrocatalysts with high activity and selectivity remains a significant challenge. In this work, we designed a feasible strategy involving the use of an In-MOF as a sacrificial template, which was pyrolytically transformed into Ce-doped In₂O₃ with varying doping ratios <i>via</i> controlled Ce doping. The optimized Ce_0.85-In₂O₃ catalyst demonstrated outstanding performance, achieving a high formate faradaic efficiency of 92.05% and a current density of -100.98 mA cm^-2. Experimental results revealed that the abundant oxygen vacancies in the catalyst and electron transfer between the constituents synergistically enhanced catalytic activity and formate selectivity. <i>In situ</i> attenuated total reflectance surface enhanced infrared absorption spectroscopy (ATR-SEIRAS) tests validated that Ce-doped In₂O₃ facilitates the formation of key formate intermediates at lower applied potential. This work provides new insights for exploring the application of metal-doped MOF derivatives in the electrocatalytic CO₂ reduction reaction.