Penetration electrode promotes asymmetric coupling with balanced adsorption for ampere-level CO2-to-C2+ conversions

The electrochemical reduction of CO 2 to value-added chemicals, such as multi-carbon (C 2+ ) compounds, using green electricity provides a sustainable route to renewable energy consumption and CO 2 emission abatement simultaneously. Yet how to enhance the selectivity of C 2+ compounds under ampere-level current densities remains a significant challenge. Addressing this limitation requires optimizing the adsorption balance of the critical *CO intermediate with CO 2 surface coverage at the triphasic reaction interface. Herein, a stable Zn-doped-Cu active sites was constructed by hydrothermal process over hollow-fiber penetration electrode (Zn-Cu HPE) with balanced adsorption for tailoring the *CO coverage and configuration to facilitate asymmetric C–C coupling. Thus, a C 2+ faradaic efficiency of 81.2% with a total current density of 2.5 A cm −2 at −1.1 V vs. RHE was achieved, outperforming state-of-the-art electrocatalysts. Experimental results and theoretical simulations demonstrated that not only the Zn-doped-Cu active sites over Zn-Cu HPE but also the adsorption dynamic equilibrium favor the asymmetric C-C coupling of *CO and *CHO intermediates, promoting the selectivity and activity of C 2+ products. This work offers a promising strategy of electrode design for efficient CO 2 -to-C 2+ conversions. Hydrothermally constructed Zn-doped-Cu active sites over Zn-Cu HPE with balanced adsorption optimize *CO coverage and configuration, achieved efficient and stable electrical reduction of carbon dioxide to multi-carbon products at ampere-level current density. By regulating the CO 2 feed concentration, the adsorption dynamic equilibrium favors the asymmetric C-C coupling of *CO and *CHO intermediates, promoting the selectivity and activity of C 2+ products. • Hydrothermally constructed Zn-doped-Cu active sites over hollow-fiber penetration electrode with balanced adsorption optimize *CO coverage and configuration, achieving an 81.2% C 2+ faradaic efficiency at 2.5 A cm -2 . • By regulating the CO 2 feed concentration, the adsorption dynamic balance equilibrium be established, which effectively promotes asymmetric *CO-*CHO coupling. • In-situ characterization and DFT verified the promoting effect of the Zn-doped Cu active sites and dynamic adsorption balance on asymmetric coupling.