In-situ constructed Cu/CuNC interfaces for low-overpotential reduction of CO2 to ethanol

Electrochemical CO2 reduction (ECR) to high-value multi-carbon (C2+) products is critical to sustainable energy conversion, yet the high energy barrier of C-C coupling causes catalysts to suffer high overpotential and low selectivity toward specific liquid C2+ products. Here, the electronically asymmetric Cu-Cu/Cu-N-C (Cu/CuNC) interface site is found, by theoretical calculations, to enhance the adsorption of *CO intermediates and decrease the reaction barrier of C-C coupling in ECR, enabling efficient C-C coupling at low overpotential. The catalyst consisting of high-density Cu/CuNC interface sites (noted as ER-Cu/CuNC) is then accordingly designed and constructed in situ on the high-loading Cu-N-C single atomic catalysts. Systematical experiments corroborate the theoretical prediction that the ER-Cu/CuNC boosts electrocatalytic CO2-to-ethanol conversion with a Faradaic efficiency toward C2+ of 60.3% (FEethanol of 55%) at a low overpotential of -0.35 V. These findings provide new insights and an attractive approach to creating electronically asymmetric dual sites for efficient conversion of CO2 to C2+ products. Cu-Cu/Cu-N-C multiatomic sites are discovered and achieved to synergistically promote the electrochemical reduction of CO2 into ethanol at low overpotentials by effectively lowering the energy barrier of C-C coupling.

Automated summary

The electronically asymmetric Cu-Cu/Cu-N-C interface site enhances the adsorption of *CO intermediates and lowers the reaction barrier of C-C coupling in electrochemical CO2 reduction (ECR), enabling efficient C-C coupling at low overpotential. The high-density Cu/CuNC interface sites (ER-Cu/CuNC) catalyst boosts the electrocatalytic CO2-to-ethanol conversion with a Faradaic efficiency toward C2+ of 60.3% (FEethanol of 55%) at a low overpotential of -0.35 V. These findings provide new insights into the efficient conversion of CO2 to C2+ products.