Bioinspired molecule-functionalized Cu with high CO adsorption for efficient CO electroreduction to acetate.

Abstract

Electrochemical reduction of carbon dioxide (CO2) or carbon monoxide (CO) to valuable multi-carbon (C2+) products like acetate is a promising approach for a sustainable energy economy. However, it is still challenging to achieve high activity and selectivity for acetate production, especially in neutral electrolytes. Herein, a bioinspired hemin/Cu hybrid catalyst was developed to enhance the surface *CO coverage for highly efficient electroreduction of CO to acetate fuels. The hemin/Cu electrocatalyst exhibits a remarkable faradaic efficiency of 45.2% for CO-to-acetate electroreduction and a high acetate partial current density of 152.3 mA cm-2. Furthermore, the developed hybrid catalyst can operate stably at 200 mA cm-2 for 14.6 hours, producing concentrated acetate aqueous solutions (0.235 M, 2.1 wt%). The results of in situ Raman spectroscopy and theoretical calculations proved that the Fe-N4 structure of hemin could enhance the CO adsorption and enrich the local concentration of CO, thereby improving C-C coupling for acetate production. In addition, compared to the unmodified Cu catalysts, the Cu catalysts functionalized with cobalt phthalocyanine with a Co-N4 structure also exhibit improved acetate performance, proving the universality of this bioinspired molecule-enhanced strategy. This work paves a new way to designing bioinspired electrolysis systems for producing specific C2+ products from CO2 or CO electroreduction.