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ABSTRACT Electrochemical carbon dioxide reduction (CO 2 RR) has emerged as a promising strategy for CO 2 utilization and as a means of storing surplus renewable electricity in chemical form. Among the possible CO 2 RR products, CO is particularly significant because it serves as a key platform molecule for the downstream synthesis of hydrocarbons and oxygenates. However, CO 2 RR in aqueous systems is fundamentally constrained by limited interfacial CO 2 availability and the challenge of stabilizing key reaction intermediates, especially in conventional H‐type cell configurations, which restricts achievable activity and selectivity. Here, we report a comprehensive investigation of Ag‐based catalysts operated in conventional high‐pressure H‐type cells, demonstrating their high intrinsic activity for CO production. Under 5.0 MPa CO 2 , oxide‐derived Ag (OD‐Ag) electrode achieves a total current density of −200 mA cm –2 and a Faraday efficiency of CO (FE CO ) of 90.0% at a low overpotential of −1.3 V (vs. RHE), representing one of the highest performances reported under similar reactor configurations. Mechanistic insights reveal that CO formation proceeds through a *COOH‐mediated pathway, with elevated pressure substantially enhancing intermediate coverage and suppressing the competing hydrogen evolution reaction. These findings highlight the critical role of CO 2 pressure in modulating both reaction pathways and catalytic selectivity. Overall, this work demonstrates that high‐pressure CO 2 RR conditions markedly improve CO selectivity and activity over Ag electrodes, providing a powerful and industrially relevant route toward high‐rate CO production and offering valuable guidance for the design of next‐generation high‐pressure electrochemical CO 2 conversion systems.
Ahmed et al. (Tue,) studied this question.