Copper‐Zinc Bimetallic Two‐Dimensional Conjugated Coordination Polymers for Highly‐Selective Electrochemical CO ₂ Reduction to Ethanol

ABSTRACT Copper‐based catalysts are the most promising catalysts for their ability to electrochemically prepare multi‐electron C 2+ products like ethanol (C 2 H 5 OH). However, the challenges persist in achieving high yields and selectivity, attributed to the unstable intermediates during the CO 2 reduction reaction (CO 2 RR). Here, we report layer‐stacked two‐dimensional conjugated coordination polymers (2D c‐CPs) with spatially separated Cu/Zn‐S 4 bi‐active sites (named as BHT‐Cu x ‐Zn y , x + y = 1) as electrocatalysts for addressing the above challenges of low Faradaic efficiency (FE) and subpar selectivity for ethanol production. Notably, the resultant BHT‐Cu 0.8 ‐Zn 0.2 2D c‐CP exhibits boosting electrochemical selective conversion of CO 2 to C 2 H 5 OH with a remarkable FE of 92.3 ± 2.4% at 126.7 mA cm −2 in a flow‐cell, with stability maintained over 150 h, superior to the thus‐far‐reported Cu‐based electrocatalysts. The integration of Zn enhances the catalytic activity and the interaction strength of Cu with key intermediate compounds. Benefited from the high selectivity, we further present a carbon efficiency of 73% for the conversion of CO 2 to C 2 H 5 OH, along with a full‐cell energy efficiency of 52%. Additionally, the energy cost is calculated at 56.6 GJ per tonne of C 2 H 5 OH, which is the lowest reported among the existing CO 2 electrolysis systems for C 2 H 5 OH production.