Synergistic Effect of Metal Doping and Tethered Ligand Promoted High‐Selectivity Conversion of CO2 to C2 Oxygenates at Ultra‐Low Potential

Abstract

Effectively controlling the selectivity of C2 oxygenates is desirable for electrocatalytic CO2 reduction. Copper catalyst has been considered as the most potential for reducing CO2 to C2 products, but it still suffers from low C2 selectivity, high overpotential, and competitive hydrogen evolution reaction (HER). Here, we propose a design strategy to introduce a second metal that weakly binds to H and a functional ligand that provides hydrogen bonds and protons to achieve high selectivity of C2 oxygenates and effective suppression of HER on the Cu(100) surface simultaneously. Seven metals and eleven ligands are screened using first‐principles calculations, which shows that Sn is the most efficient for inhibiting HER and cysteamine (CYS) ligand is the most significant in reducing the limiting potential of *CO hydrogenation to *CHO. In the post C−C coupling steps, a so‐called “pulling effect” that transfers H in the CYS ligand as a viable proton donor to the C2 intermediate to form an H bond, can further stabilize the OH group and facilitate the selection of C2 products toward oxygenates. Therefore, this heterogeneous electrocatalyst can effectively reduce CO2 to ethanol and ethylene glycol with an ultra‐low limiting potential of −0.43 V. This study provides a new strategy for effectively improving the selectivity of C2 oxygenates and inhibiting HER to achieve advanced electrocatalytic CO2 reduction.