Facile synthesis of porous Cu-Sn alloy electrode with prior selectivity of formate in a wide potential range for CO2 electrochemical reduction

CO2 electroreduction is regarded as a potential way to mitigate CO2 level and produce value-added chemicals. Although Cu-Sn bimetallic electrodes show an excellent selectivity towards targeted formate or CO, the better performance is only achieved in a narrow potential range. Herein, porous Cu6.26Sn5 electrode is prepared. Alloying Cu with Sn atoms tunes the electronic structure of catalyst, which balances the adsorption and protonation of CO2*-intermediate. The unique rice spike-like microstructure intensifies the local electric field to raise the CO2 concentration at the reaction sites. As a result, it exhibits a superior selectivity towards formate with the maximum faradaic efficiency (FEformate) of 97.8 +/- 2.4 %. The better selectivity (FEformate over 80 %) is maintained over a wider potential range of 600 mV, which outperforms the majority of reported Cu-Sn bimetallic electrodes. This research provides a promising way to concurrently regulate morphological and electronic structure of alloy electrodes for efficient CO2 electroreduction.

Automated summary

The study prepared a porous Cu6.26Sn5 electrode, tuning the electronic structure of the catalyst by alloying Cu with Sn atoms to balance the adsorption and protonation of intermediates, resulting in increased CO2 concentration and selectivity, promising efficient CO2 electroreduction.