Local Steric Hindrance for CO2 Electroreduction at a Thermodynamic Potential and Wide Working Window

To improve the energy-conversion efficiency and adaptability between a CO₂ 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 CO₂ during electroreduction including local CO₂ transport, adsorption, activation, hydrogenation, and product desorption. Significantly, a CO₂ 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 CO₂ 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.