Intermetallic charge redistribution restructures the oxygen-bound intermediate network for efficient ethylene electrosynthesis.

Abstract

The precise regulation of Cu surface electronic structure governs C-C coupling pathways and intermediate adsorption to enhance ethylene selectivity. However, how heteroatom dopants modulate the flux of oxygen-bound intermediates remains unclear. Herein, we establish a predictive framework based on six dopant elements' electron orbital characteristics, demonstrating that p-orbital metal doping enables favorable orbital-center proximity for hybridization with Cu active centers. Al-incorporated Cu balances adsorption affinities for *CO, *H, and *O, thereby reducing the *OCCO formation barrier. Controlled Al doping in CuAl single-atom alloy (CuAl_SA) induces lattice expansion and d-band center downshifting (Δε_Cu = -2.94 eV), achieving favorable d-p orbital proximity (δ_{d, p} = -1.00 eV) and a low C-C coupling energy barrier (ΔE = 0.30 eV). In situ Raman spectroscopy confirms that the optimized d-p proximity promotes C-C bond formation and *OCCO hydrogenation to *CH₂CHO, redirecting intermediate flux from methane toward ethylene. CuAl_SA consequently exhibits 78.8% ethylene Faraday efficiency under pure CO₂ and retains 70.2% under 15% CO₂. This work establishes a strategy for directing oxygen-bound intermediates in CO₂-to-C₂H₄ electrosynthesis.