Boosting Electrocatalytic Hydrogenation of Phenylacetylene via Accelerating Water Electrolysis on a Cr-Cu₂O Surface

Electrochemical alkyne reduction with H₂O as a hydrogen source represents a sustainable route for value-added olefin production. However, the reaction efficiency is hampered by the high voltage and low activity of Cu electrodes due to their weak adsorbed hydrogen (*H) generation property. In this article, we present the enhanced electrocatalysis of phenylacetylene to styrene over a highly dispersive Cr-doped Cu₂O nanowire (Cr-Cu₂O) cathode. The Cr-Cu₂O demonstrates improved catalytic activity compared to pure Cu₂O, achieving a high conversion of about 94.7% and a selectivity of 87.9% with a Faraday efficiency of 64.5% at a low potential of -1.15 V vs Hg/HgO. The combination of electrochemical characterization techniques and theoretical calculations demonstrated the key role of introduced Cr atoms in lowering the activation energy barrier of surface water electrolysis to *H and facilitating the adsorption of phenylacetylene, which promotes the effective hydrogenation of phenylacetylene with *H via an electrocatalytic hydrogenation mechanism. In short, this work provides a feasible strategy to enrich interfacial *H, thus improving the semihydrogenation performance of phenylacetylene.