Regulating surface In–O in In@InO core-shell nanoparticles for boosting electrocatalytic CO2 reduction to formate

To solve the excessive emission of CO 2 caused by the excessive use of fossil fuels and the corresponding environmental problems, such as the greenhouse effect and climate warming, electrocatalytic CO 2 reduction to liquid fuel with high selectivity is of huge significance for energy conversion and storge. Indium has been considered as a promising and attractive metal for the reduction of CO 2 to formate. However, the current issues, such as low selectivity and current activity, largely limit the industrial application for electrocatalytic CO 2 reduction, the design optimization of the catalyst structure and composition is extremely important. Herein, we develop a facile strategy to regulate surface In–O of In@InO x core-shell nanoparticles and explore the structure-performance relationship for efficient CO 2 -to-formate conversion though air calcination and subsequent in situ electrochemical reconstruction, discovering that the surface In–O is beneficial to stabilize the CO 2 intermediate and generate formate. The optimized AC-In@InO x -CNT catalyst exhibits a C 1 selectivity up to 98% and a formate selectivity of 94% as well as a high partial formate current density of 32.6 mA cm −2 . Furthermore, the catalyst presents an excellent stability for over 25 h with a limited activity decay, outperforming the previously reported In-based catalysts. These insights may open up opportunities for exploiting new efficient catalysts by manipulating their surface. A facile air calcination and in situ reconstruction strategy is developed to regulate the surface In–O sites in core-shell In@InO x catalysts for revealing its effects on electrocatalytic CO 2 RR.