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

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 (Cu₃P) nanoparticles on MXene nanosheets (Ti₃C₂/Cu₃P) for a stable EHAE process at industrial currents using membrane electrode assembly (MEA) system. Specifically, the Ti₃C₂/Cu₃P 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 Cu₃P and Ti₃C₂ MXene prevent the agglomeration and dissolution of Cu₃P nanoparticles during long-term EHAE process. Notably, in a 4 cm² MEA, Ti₃C₂/Cu₃P 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 Ti₃C₂/Cu₃P facilitates water dissociation and synergistically enhances the adsorption of acetylene and active hydrogen (H^*), thereby accelerating the kinetics of EHAE process.