Concave Surface-Enriched Reactant Boosts Electrocatalytic C2H4 Production from Coal-Derived C2H2 via π-Electron Delocalization Effect

Electrocatalytic semihydrogenation of acetylene (C 2 H 2 ) provides a facile and petroleum-independent pathway for ethylene (C 2 H 4 ) production. However, the reliance on the preseparation and concentration of raw coal-derived C 2 H­ 2 hinders its economic potential. Here, density functional theory calculations demonstrate that a concave surface leads to a polarization electric field, which is beneficial for enriching the electrophilicity C 2 H­ 2 and is suitable for direct conversion of raw coal-derived C 2 H 2 . Then, a porous concave carbon-supported Cu nanoparticles (Cu-PCC) electrode is designed to enrich the feeding C 2 H 2 gas. As a result, the as-prepared electrode enables a 91.7% C 2 H 4 Faradaic efficiency and 81.26% C 2 H 2 conversion under a simulated raw coal-derived C 2 H 2 atmosphere (~15%) at a current density of 420 mA cm −2 , greatly outperforming its counterpart without concave surface supports. Moreover, a series of characterizations reveal that the strengthened intermolecular π conjugation caused by the increased C 2 H 2 coverage leads to the delocalization of π electrons in C 2 H 2 , consequently promoting C 2 H 2 activation, suppressing HER competition and enhancing C 2 H 4 selectivity.