Bridging Liquid and Gas Phase Catalysis for Abiotic CO ₂ Conversion to Prebiotic Organics Over Mesoporous Silica‐Supported Ni–Co Catalysts

Reduced carbon species such as formate and methane are widely observed in serpentinizing hydrothermal systems, suggesting that abiotic CO 2 hydrogenation can proceed on native metal surfaces or mineral‐supported catalysts. Here, we systematically evaluate SBA‐15 mesoporous silica‐supported Ni–Co catalysts as model systems for the abiotic conversion of CO 2 to prebiotic organic molecules under both liquid‐ and gas‐phase conditions. Under liquid‐phase conditions (25°C, 63 bar), all catalysts promote CO 2 reduction to formate and ethanol at millimolar concentrations using water as the hydrogen source, while the addition of molecular H 2 enhances formate formation at the expense of ethanol production. In contrast, gas‐phase reactions (230–270°C, 20 bar) favor CO 2 conversion to CO, methanol, methane, and ethane. Across both phases, catalytic activity and product selectivity exhibit a pronounced dependence on the Ni⋅Co composition, highlighting the critical role of bimetallic interactions. Notably, water strongly modulates CO 2 adsorption and the resulting product distribution, underscoring its dual function as both solvent and reactive species. These findings provide insight into phase‐dependent CO 2 hydrogenation pathways over Ni⋅Co catalysts and offer a catalytic framework for understanding abiotic routes to prebiotic carbon compounds.