Cu/LaF3 Interfaces Boost Electrocatalytic CO-to-Acetate Conversion

The electrochemical reduction of carbon monoxide (COR) holds significant promise as an ecofriendly approach for producing valuable chemicals, such as acetate. However, the current unsatisfactory activity and selectivity of this process hinder its future implementation. In this study, we develop and study a catalyst composite comprising lanthanum fluoride (LaF3) crystal support and copper (Cu) as the active phase. Under typical COR conditions, the LaF3–Cu electrocatalyst demonstrates remarkable selectivity, exceeding 40% at −0.95 V vs. RHE, with a partial current density of over 280 mA cm–2 for acetate production. In contrast, the pristine Cu catalyst achieves only 56 mA cm–2 at −1.12 V vs. RHE with a low selectivity of <10%. Through detailed kinetic and computational studies, we attribute this remarkable enhancement in both selectivity and activity toward acetate formation to the stabilization of the ethenone intermediate at the LaF3/Cu interface during COR. Inspired by this finding, we extended this substrate effect to a bimetallic copper–silver catalyst, which led to a notable increase in acetate selectivity (>66%) under the same conditions. Overall, our findings introduce a universal strategy based on substrate effects for the development of selective and active COR catalysts.