Newly generated Cu2O[sbnd]Cu interface for CO2 electroreduction in the presence of reconstructed aluminum hydroxide

Abstract

The electrochemical CO2 reduction reaction (eCO2RR) to C2+ products is attractive but challenging. Herein, flower-like Al0.9/CuO composed of modified CuO nanosheets was synthesized by a hydrothermal synthesis method under the conditions of high alkaline concentration, in which aluminum hydroxide was dissolved and regenerated on CuO nanosheets. The as-obtained flower-like Al0.9/CuO presents a higher faradaic efficiency of multicarbon (C2+) products 77.6% at -0.95 V vs. RHE for eCO2RR in an H-type cell than other flower-like Alx/CuO and achieves C2+ product faradaic efficiency of 75.2% and partial current density of 752.5 mA cm−2 in a flow cell. Characterization results show that Cu(I)/Cu(0) interface is formed along with the existence of oxygen defects and d-band center shifting toward low-energy region on flower-like Al0.9/CuO compared with traditional CuO nanosheets. Evenly dispersed Cu(0) and oxygen vacancy on the nanosheet promote the absorption and activation of CO2, while Cu(I) adjacent to Cu(0) regulated by aluminum species improves the adsorption of *CO intermediates, beneficial to the CC coupling to C2+ products in eCO2RR. Therefore, this work provided a strategy to efficiently modulate the distribution of electron and ingredient on the copper based electrocatalyst to improve the performance of C2+ products in eCO2RR.