The manuscript reported a surface prereduction method for CuCo catalysts to enhance the efficiency and selectivity of electrochemical carbon dioxide reductio. The authors have done well in responding to the reviewer’s comment and therefore merit a publication in Sustainable Energy & Fuel upon addressing some of the below comments:
1. While the catalyst before and after the pre-reduction has been thoroughly analysed, the catalyst after electrochemical should also be characaterised to further understand if there is any further changes during electrochemical CO2 reduction.
2. Detailed experimental methods for all electrochemical measurements including electrochemical CO2 reduction should be provided. How long does each cycle of electrochemical CO2 reduction run for?
3. What is the current density achieved during the electrochemical CO2 reduction reaction at different potentials? The CO2 reductions were performed from -0.45 V to -0.95 V vs. RHE, while LSV provided is measured from 0.6 V to -0.3 V vs RHE? The author should provide the I-t curve of every electrochemical CO2 reduction experiment performed under different applied potential.
4. It is also interesting to see if the performance and selectivity can be further improved by lowering the applied potential to -0.35 V vs. RHE or lower.

The manuscript has been improved upon revision and can be accepted for publication.