Electrocatalytic Acetylene Semi-Hydrogenation to Ethylene with High Energy Efficiency

Abstract

Electrocatalytic acetylene semi-hydrogenation (EASH) provides a petroleum-independent strategy for ethylene production. However, the challenges of high overpotentials and strong hydrogen evolution competition reaction over conventional electrocatalysts at industrial current densities result in substantial energy consumption, limiting the practical application of EASH technology. Herein, zinc-doped copper catalysts are designed and prepared via a facile impregnation and electroreduction relay method. The as-prepared Cu-2.7Zn catalyst exhibits an ethylene partial current density of −0.29 A cm⁻² with a Faradaic efficiency of 96 % and a reaction potential of −0.62 V versus reversible hydrogen electrode (RHE), surpassing the previously reported electrocatalysts. The combined results of experimental tests and theoretical calculations demonstrate zinc doping significantly enhances acetylene adsorption and accelerates reaction kinetics, leading to a notable decrease in overpotential. Furthermore, the increased *H-*H binding energy barrier and the improved ethylene desorption on Cu-2.7Zn effectively suppress hydrogen evolution and acetylene over-hydrogenation, contributing to the enhancement of ethylene Faradaic efficiency.