Local Steric Hindrance for CO<sub>2</sub> Electroreduction at a Thermodynamic Potential and Wide Working Window
Ming Li, Kang Yang, Yuntong Sun, Tianqi Gao, Zhihao Nie, Sheng Chen, Qiang Li, Jingjing Duan
Abstract
Abstract To improve the energy‐conversion efficiency and adaptability between a CO 2 electroreduction system and intermittent renewable energy, small onset potentials, and wide working windows are highly important. Here, three indium metal–organic frameworks (In‐MOFs) have been projected using different ligands to adjust the local steric hindrance and electronic structure of In nodes, manipulating the whole workflow of CO 2 during electroreduction including local CO 2 transport, adsorption, activation, hydrogenation, and product desorption. Significantly, a CO 2 electroreduction to formate process promoted by 2,5‐TDC In‐MOF shows an onset potential of −0.1 V versus RHE around the therymodynamic potential, over 90% FE foramte in a wide current‐density window from 0.1 to 0.9 A cm −2 . Driven by solar cells, the system displays a high solar‐to‐chemical efficiency of 17.39%. In depth mechanism study indicates that the local CO 2 transport and adsorption of all In‐MOFs are thermodynamically and kinetically favorable, while the energy barrier of potential‐determine step (*HCOOH desorption) is the lowest for 2,5‐TDC In‐MOF.