Enhanced CO Affinity on Cu Facilitates CO2 Electroreduction toward Multi-Carbon Products.

Abstract

Electrochemical CO2 reduction reaction (CO2 RR) is a promising strategy for waste CO2 utilization and intermittent electricity storage. Herein, it is reported that bimetallic Cu/Pd catalysts with enhanced *CO affinity show a promoted CO2 RR performance for multi-carbon (C2+) production under industry-relevant high current density. Especially, bimetallic Cu/Pd-1% catalyst shows an outstanding CO2 -to-C2+ conversion with 66.2% in Faradaic efficiency (FE) and 463.2mA cm-2 in partial current density. An increment in the FE ratios of C2+ products to CO for Cu/Pd-1% catalyst further illuminates a preferable C2+ production. In situ Raman spectra reveal that the atop-bounded CO is dominated by low-frequency band COon Cu/Pd-1% that leads to C2+ products on bimetallic catalysts, in contrast to the majority of high-frequency band COon Cu that favors the formation of CO. Density function theorycalculation confirms that bimetallic Cu/Pd catalyst enhances the *CO adsorption and reduces the Gibbs free energy of the CC coupling process, thereby favoring the formation of C2+ products.