Altering the CO2 electroreduction pathways towards C1 or C2+ products via engineering the strength of interfacial Cu‐O bond

Abstract

Copper (Cu)‐based catalysts have established their unique capability for yielding wide value‐added products from CO2. Herein, we demonstrate that the pathways of the electrocatalytic CO2 reduction reaction (CO2RR) can be rationally altered toward C1 or C2+ products by simply optimizing the coordination of Cu with O‐containing organic species (squarate (C4O4) and cyclohexanhexanone (C6O6)). It is revealed that the strength of Cu‐O bonds can significantly affect the morphologies and electronic structures of derived Cu catalysts, resulting in the distinct behaviors during CO2RR. Specifically, the C6O6‐Cu catalysts made up from organized nanodomains shows a dominant C1 pathway with a total Faradaic efficiency (FE) of 63.7% at ‐1.0 V (versus reversible hydrogen electrode, RHE). In comparison, the C4O4‐Cu with an about perfect crystalline structure results in uniformly dispersed Cu‐atoms, showing a notable FE of 65.8% for C2+ products with enhanced capability of C‐C coupling. The latter system also shows stable operation over at least 10 h with a high current density of 205.1 mA cm‐2 at ‐1.0 VRHE, i.e. is already at the boarder of practical relevance. This study sheds light on the rational design of Cu‐based catalysts for directing the CO2RR reaction pathway.