• • Faradaic efficiency (FE) for ethylene reaches 64.6% at a partial current density of 646 mA cm-2, satisfying industrial current density thresholds (>200 mA cm-2) while maintaining high selectivity, which directly addresses the trade-off between selectivity and productivity that plagues conventional Cu catalysts.
• • The asymmetric C–C coupling energy barrier is reduced to 0.74 eV, a value substantially lower than that of undoped CuO (typically >1.0 eV), enabling efficient ethylene formation by overcoming the kinetic bottleneck that limits C2+ production at high current densities.
• • Phosphorus doping generates abundant lattice defects and oxygen vacancies, as confirmed by structural characterizations, which enhance *CO adsorption and stabilize the *OCCHO intermediate through P–O/Cu–C dual-site adsorption, a mechanism that suppresses competing hydrogen evolution reaction (HER) and improves ethylene selectivity.
• • The MOF-assisted in situ doping strategy yields a catalyst with a partial current density of 646 mA cm-2 for ethylene, demonstrating potential for scalable deployment in industrial CO2 electrolyzers where ampere-level current densities are required for economic viability.