biostudies-literatureBai LNational Natural Science Foundation of China (National Science Foundation of China)1020https://www.ebi.ac.uk/biostudies/studies/S-EPMC12848049biostudies-literatureUnknown17(1)Electroconversion of acetylene towards polymer-grade ethylene (EAE) is recognized as a promising substitution for thermo-catalytic route. The excessive active-hydrogen supplies a high current density induces the conspicuous hydrogen evolution, reducing the ethylene Faradaic efficiency (FE). Here, we develop a Cu-Pd single atom alloy (SAA) catalyst, achieving a 90.5% FE with a large ethylene partial current density of -1.16 A cm^-2, and maintain stability for 110 h at -0.2 A cm^-2 in the flow-cell system. In membrane electrode assembly, Cu-Pd SAA delivers a 90.1% ethylene FE and ~100 % conversion at -2.5 A (-0.1 A cm^-2), along with 500 h stability for crude ethylene purification. Combined in-situ spectroscopy and DFT calculation reveal that the catalyst faciliNature communicationsAmpere-level electroconversion of acetylene towards polymer grade ethylene via Pd-H mediated non-spillover hydrogenation.PMC1284804922275147523012891240422521902150Li DZheng LBai LHan XLin YKong CBai JQu YShi JLeng KZhao YShe MfalseAmpere-level electroconversion of acetylene towards polymer grade ethylene via Pd-H mediated non-spillover hydrogenation.Electroconversion of acetylene towards polymer-grade ethylene (EAE) is recognized as a promising substitution for thermo-catalytic route. The excessive active-hydrogen supplies a high current density induces the conspicuous hydrogen evolution, reducing the ethylene Faradaic efficiency (FE). Here, we develop a Cu-Pd single atom alloy (SAA) catalyst, achieving a 90.5% FE with a large ethylene partial current density of -1.16 A cm^-2, and maintain stability for 110 h at -0.2 A cm^-2 in the flow-cell system. In membrane electrode assembly, Cu-Pd SAA delivers a 90.1% ethylene FE and ~100 % conversion at -2.5 A (-0.1 A cm^-2), along with 500 h stability for crude ethylene purification. Combined in-situ spectroscopy and DFT calculation reveal that the catalyst facili2025-01-01T00:00:00Z2025 Dec2026-06-10T09:05:59.969Z2026-06-10T03:11:47.072ZS-EPMC128480494146164810.1038/s41467-025-67764-8