Accelerating water activation kinetics via sulfur-anchoring for ampere-level ethylene electrosynthesis in membrane electrode assembly electrolyzer

Electrocatalytic semi-hydrogenation of acetylene to ethylene under ambient conditions represents a promising approach for sustainable chemical production. However, the low electrosynthesis efficiency and poor product selectivity hinder their large-scale industrial applications, especially at ampere-level current densities . Here, we develop a sulfur-engineered single-atom copper supported on oxygen-functional Ti 3 C 2 O x MXene nanosheets (Cu-SA/S-MXene) for efficient, stable ethylene electrosynthesis, achieving a high Faradaic efficiency of 94.3 ± 1.9 % with a partial current density of 0.53 A cm −2 in a flow cell, while maintaining ethylene selectivity above 80 % in a membrane electrode assembly electrolyzer across a voltage range of 2.0–2.8 V associated with an ampere-level current density of 1.6 A cm −2 at 3.0 V. A combination of theoretical computations and in situ spectroscopy characterizations unveil that the introduction of S species in the MXene accelerates proton-feeding from water dissociation process for providing sufficient reactive hydrogen, and strengthens electron transfer and interaction between Cu active site and adsorbed acetylene molecules. Furthermore, a preliminary techno-economic analysis evidences both the economic feasibility and sustainability of the ethylene electrosynthesis process. This work paves the way for a more efficient and sustainable ethylene production strategy, potentially revolutionizing industrial electrosynthesis. Accelerated proton-feeding from water dissociation enables highly efficient acetylene-to-ethylene conversion at ampere-level currents in membrane electrode assembly electrolyzer, demonstrating the potential for sustainable industrial-scale ethylene electrosynthesis. • The Cu-SA/S-MXene achieves a selectivity of 94.3 % for ethylene electrosynthesis. • It maintains > 80 % ethylene selectivity at an ampere-level current density. • This offers insights into catalyst design to enhance hydrogenation applications.