Insight into the Electrochemical CO-to-Ethanol Conversion Catalyzed by CuS Nanocrystal-Decorated Cu Nanosheets.

Ethanol (CHOH) is an economically ideal C product in electrochemical CO reduction. However, the CO-to-CHOH conversion yield has been rather low and the underlying catalytic mechanism remains vague or unexplored in most cases. Herein, by decorating small CuS nanocrystals uniform ly on Cu nanosheets, three desirable features are integrated into the electrocatalyst, including a relatively high positive local charge on Cu (Cu), abundant interfaces between Cu and zero-valence Cu, and a non-flat, stepped catalyst surface, leading to the promoted affinity of *CO, decreased *COCO formation barrier, and thermodynamically preferred *CHCHO-to-*CHCHO conversion. As a result, a high partial current density of ∼20.7 mA cm and a Faraday efficiency of 46% for CHOH are delivered at -1.2 V vs reversible hydrogen electrode in an H-cell containing a 0.1 M KHCO solution. This work proposes an efficient strategy for the high-yield CO-to-CHOH conversion, emphasizing the promise for the industrial production of alcohol and related products from CO.