Optimized catalytic properties and reactant adsorption energy play a
crucial role in promoting CO2 electrocatalysis. Herein, Cu7S4/Cu
undergoes in situ dynamic restructuring to generate S-Cu2O/Cu hybrid
catalyst for effective electrochemical CO2 reduction to formate that
outperforms Cu2O/Cu and Cu7S4. Thermodynamic and experimental analyses
reveal that the optimized adsorption of the HCOO* intermediate on
S-Cu2O/Cu is regulated and the H2 pathway (surface H) is suppressed by
S-doping. Meanwhile, Cu7S4/Cu nanoflowers create abundant grain
boundaries for ECR and strengthen the CO2 adsorption by inducing Cu.
These findings provide a new perspective on synthetic methods for
various electrocatalytic reduction processes.