Selective Electroreduction of CO₂ to C₂₊ Alcohols Using Graphitic Frustrated Lewis Pair Catalyst

Abstract

Efficient electroreduction of CO2 to multicarbon products is a complicated reaction because of the high energy barriers for the CO2 activation and C–C coupling. Here, we design a graphitic frustrated Lewis pair catalyst doped with boron and nitrogen (BN-GFLP) for reducing the amount of CO2 to multicarbon products. Multicarbon (C2+) biofuels (i.e., ethanol and n-propanol) are identified as the major products with a C2+ Faradaic efficiency of 87.9% at a partial current density of −6.0 mA/cm2 (C2+ Faradaic efficiency of 70.7% at a partial current density of −10.6 mA/cm2). Furthermore, density functional theory calculations reveal that the dual binding site of FLP reduces the reaction free energies required for CO2 activation and C–C coupling. Consequently, energetically favorable CO2 reduction pathways are proposed, and selectivities for the production of ethanol and n-propanol are determined. Based on our results, we propose a molecular design strategy for the selective CO2 reduction catalysts aimed at facilitating C2+ alcohols production.