Granular protruded irregular Cu2O catalysts for efficient CO2 reduction to C2 products

Abstract

The electrochemical reduction of carbon dioxide (CO2) to high-energy multi-carbon compounds is a significant challenge. Efforts have been made to design efficient catalysts for high selectivity toward multi-carbon products. In this study, granular protruded irregular Cuprous oxide (Cu2O) nanoparticles were synthesized using a simple water bath wet chemical reduction method. Polyethylene glycol (PEG) was utilized as a directing agent to control the morphology of Cu2O in the process. The optimized irregular Cu2O (ir-Cu2O) catalyst exhibits a remarkable faraday efficiency of 69.3% (±3.3%) for double-carbon compounds (C2), which is significantly higher than that of polyhedral Cu2O (p-Cu2O) (50.4%±1.1%) synthesized without adding PEG. Cu2O nanoparticles with irregular shape featuring randomly distributed spherical protrusions offer more active sites for CO2 adsorption than p-Cu2O catalysts, which is beneficial for the conversion of CO2 to C2. In addition, in situ infrared spectra reveal that ir-Cu2O reduces CO2 to C2 mainly through the coupling of the CO* and CHO*, thereby promoting the formation of C2. These findings provide valuable insights for the design of high-efficiency electrocatalysts for CO2 electroreduction to C2.