Electrochemical CO Reduction to n-Propanol on Cu via Dual Weakening of CO Adsorption and C≡O Bond Strength

Abstract

Renewable-electricity-driven carbon monoxide reduction (CORR) for synthesizing multi-carbon (C2+) products offers immense appeal as a route for energy storage and carbon recycling. Yet, producing extended-carbon products such as n-propanol with high market value remains challenging due to the relative rarity of the *C2 intermediate. This paper describes a strategy for dual weakening of CO adsorption and C≡O bond strength to enhance the CORR performance for n-propanol by introducing anion-functional group-modified graphene quantum dots on Cu (Cu/GQD-X, where X represents OH, NH2, SO3, and PO4). We achieve a Faradaic efficiency (FE) of 45.3% and a full-cell EE of 23% for n-propanol on GQD-SO3-modified Cu while maintaining stable performance without obvious degradation for at least 144 h in a membrane electrode assembly. Mechanism studies reveal that Cu/GQD-SO3 provides a suitable CO coverage and a weakened C≡O bond, facilitating the hydrogenation of *CO to *COH, asymmetrical *CO–COH coupling to *COCOH, and *COH–COCOH coupling for the generation of n-propanol. This work demonstrates the crucial role of dual weakening of CO adsorption and the C≡O bond in CORR for the efficient production of n-propanol and contributes significantly to understanding the mechanism of n-propanol formation.