ABSTRACT Electrocatalytic CO 2 reduction reaction (ECO 2 RR) stands as a crucial process for converting CO 2 into valuable chemicals, particularly C 2+ products. Yet, achieving high selectivity towards C 2+ chemicals remains challenging. Among the catalysts explored to date, Cu‐based catalysts with multivalent Cu are widely used for this process. However, the precise tuning of Cu‐based catalysts, especially stabilization of multivalent Cu species, remains a difficult issue for enhancing selectivity toward C 2+ products. In this work, we report an efficient Cu‐based catalyst (designated as Cu‐MOF/Cu x O/CF‐40), containing Cu‐terephthalic acid (PTA) (Cu‐MOF) generated on a Cu foil (CF) and Cu x O (Cu 2+1 O and CuO) mainly stemming from Cu‐MOF, in achieving ECO 2 RR to C 2 chemicals. The catalyst delivers a total C 2 Faradaic efficiency (FE C2 ) of up to 91.8% and a total current density of 34.6 mA·cm −2 at ‐1.1 V (vs. RHE) in 0.1 M KCl (H‐cell). The Cu 2+1 O and CuO species, with multivalent Cu properties, adsorb and activate CO 2 , and improve the electrical conductivity of the catalyst. Cu‐MOF stabilizes the multivalent feature and long‐term performance of the catalyst. In situ ATR‐FTIR and DFT calculations identify *OCCOH as the key C–C coupling intermediate. This work provides a rational design strategy for efficient, stable Cu‐based catalysts and demonstrates a single‐source route to engineer multivalent Cu sites for selective CO 2 ‐to‐C 2 conversion.
Cao et al. (Thu,) studied this question.