Toward Industrial Electrosynthesis of Ethylene: Energy‐Efficient and Stable Acetylene Semi‐Hydrogenation on a Copper Phosphide/MXene Electrocatalyst

Abstract Electrocatalytic semi‐hydrogenation of acetylene to ethylene (EHAE) using renewable electricity represents a promising alternative approach for ethylene production. However, its relatively low energy efficiency (EE) and insufficient electrocatalyst stability hinder its industrial applications. The conduct a techno‐economic analysis indicates that the EHAE process becomes profitable when the EE exceeds 22.8% at an industrial current density of 0.2 A cm −2 . Herein, we report a novel electrocatalyst featuring firmly immobilized copper phosphide (Cu 3 P) nanoparticles on MXene nanosheets (Ti 3 C 2 /Cu 3 P) for a stable EHAE process at industrial currents using membrane electrode assembly (MEA) system. Specifically, the Ti 3 C 2 /Cu 3 P electrocatalyst achieves an EE of 23.0% at 0.2 A cm −2 , demonstrating its potential for practical application and economic viability. The strong interactions between Cu 3 P and Ti 3 C 2 MXene prevent the agglomeration and dissolution of Cu 3 P nanoparticles during long‐term EHAE process. Notably, in a 4 cm 2 MEA, Ti 3 C 2 /Cu 3 P catalysts can sustain high performance for 100 h at 1.0 A with an ethylene Faradaic efficiency decay of only 0.051% per hour. Quasi in situ electron paramagnetic resonance spectroscopy and theoretical calculations indicate that Ti 3 C 2 /Cu 3 P facilitates water dissociation and synergistically enhances the adsorption of acetylene and active hydrogen (H * ), thereby accelerating the kinetics of EHAE process.