This study demonstrates the development of a trinuclear single-atom alloy catalyst (Cu0.92Sb0.8Pd0.3) for the efficient and selective conversion of CO₂ to CO using renewable electricity. The catalyst achieves a 100% (±1.5%) CO selectivity at −402 mA cm⁻² and high activity up to −1A cm⁻² in a neutral electrolyte, surpassing many state-of-the-art noble metal catalysts. The catalyst exhibits long-term stability over 528 hours at −100 mA cm⁻² with an FEₐ above 95%. Operando spectroscopy and theoretical simulations reveal that the synergistic effect of Sb and Pd atoms shifts the electronic structure of Cu, enhancing CO production and suppressing hydrogen evolution. This work challenges the monopoly of noble metals in large-scale CO₂-to-CO conversion, offering a sustainable and cost-effective solution for CO production.This study demonstrates the development of a trinuclear single-atom alloy catalyst (Cu0.92Sb0.8Pd0.3) for the efficient and selective conversion of CO₂ to CO using renewable electricity. The catalyst achieves a 100% (±1.5%) CO selectivity at −402 mA cm⁻² and high activity up to −1A cm⁻² in a neutral electrolyte, surpassing many state-of-the-art noble metal catalysts. The catalyst exhibits long-term stability over 528 hours at −100 mA cm⁻² with an FEₐ above 95%. Operando spectroscopy and theoretical simulations reveal that the synergistic effect of Sb and Pd atoms shifts the electronic structure of Cu, enhancing CO production and suppressing hydrogen evolution. This work challenges the monopoly of noble metals in large-scale CO₂-to-CO conversion, offering a sustainable and cost-effective solution for CO production.