Orbital Interactions in Co1-N-Ga1 Atomic Pairs Tailor Syngas Composition from CO2 Electroreduction for Downstream Upgrading Synthesis

Electrochemical CO2 reduction reaction (CO2RR) for syngas production (mixture of H2 and CO) driven by renewable energy is a critical strategy to reduce carbon emission and for valorization of CO2. However, it remains a major challenge to robustly modulate the H2/CO ratio under the circumstance of voltage fluctuations. Herein, we prepare Co1-N-Ga1 atomic pairs confined in a nitrogen doping carbon substrate. Combined experimental and theoretical studies reveal that the orbital interactions involved in Co1 and Ga1 atomic pairs enable the synchronous optimizations of *COOH formation and splitting to CO, thereby balancing CO2RR and the hydrogen evolution reaction. In the flow cell, the dual-atom catalysts delivered tunable H2/CO ratios (0.5, 1, 2) at >300 mA cm−2 over a wide potential window of –0.6 to –1.1 V (versus the reversible hydrogen electrode). Furthermore, in a membrane electrode assembly electrolyzer of 100 cm2, the optimal catalyst maintains the desired H2/CO ratios at 30 A total current with a syngas productivity of 12.4 L h−1. Built on this, a tandem process involving electrocatalysis and thermocatalysis delivers the upgrading synthesis of methanol, ethanol, and acetic acid with corresponding selectivities of 86.7, 82.1, and 79.5%, respectively.