Cu₇S₄/Cu nanoflowers with strong CO₂ adsorption and abundant boundaries were developed by a facile thermal reduction, which underwent in situ dynamic restructuring during ECR to generate highly active S-doped Cu₂O/Cu hybrid catalyst. Thermodynamic and experimental analysis revealed that the optimized adsorption of the HCOO^* intermediate on S−Cu₂O/Cu was regulated and surface H was suppressed by S-doping. The high activity for CO₂-to-HCOOH attributed to the strengthen CO₂ adsorption, abundant boundaries at Cu₂O/Cu interfaces, and the regulation of adsorption energy by S-doping

Abstract

Optimized catalytic properties and reactant adsorption energy played a crucial role in promoting CO₂ electrocatalysis. Herein, Cu₇S₄/Cu underwent in situ dynamic restructuring to generate S−Cu₂O/Cu hybrid catalyst for effective electrochemical CO₂ reduction to formate that outperformed Cu₂O/Cu and Cu₇S₄. Thermodynamic and in situ Raman spectra revealed that the optimized adsorption of the HCOO* intermediate on S−Cu₂O/Cu was regulated and the H₂ pathway (surface H) was suppressed by S-doping. Meanwhile, Cu₇S₄/Cu nanoflowers created abundant boundaries for ECR and strengthened the CO₂ adsorption by inducing Cu. These findings provide a new perspective on synthetic methods for various electrocatalytic reduction processes.