Selectivity regulation of CO2 electroreduction through contact interface engineering on superwetting Cu nanoarray electrodes
Electrocatalytic CO2 reduction is a promising way to mitigate the urgent energy and environmental issues, but how to increase the selectivity for desired product among multiple competing reaction pathways remains a bottleneck. Here, we demonstrate that engineering the gas–liquid–solid contact interface on the electrode surface could tailor the selectivity of CO2 reduction and meanwhile suppress H2 production through regulated reaction kinetics. Specifically, polytetrafluoroethylene (PTFE) was utilized to modify a Cu nanoarray electrode as an example, which is able to change the electrode surface from aerophobic to aerophilic state. The enriched nano-tunnels of the Cu nanoarray electrode can facilitate CO2 transportation and pin gaseous products on the electrode surface. The latter is believed to be the reason that boosts the Faradaic efficiency of liquid products by 67% and limits the H2 production to less than half of before. This interface engineering strategy also lowered H2O (proton) affinity, therefore promoting CO and HCOOH production. Engineering the electrode contact interface controls the reaction kinetics and the selectivity of products, which should be inspiring for other electrochemical reactions.
KeywordsCO2 reduction selectivity copper contact interface reaction kinetics
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This work was supported by the National Natural Science Foundation of China, the National Key Research and Development Program of China (Nos. 2016YFC0801302 and 2016YFF0204402), the Program for Changjiang Scholars and Innovative Research Team in the University, the Fundamental Research Funds for the Central Universities, and the longterm subsidy mechanism from the Ministry of Finance and the Ministry of Education of PRC. Y. X. Z. thanks the National Natural Science Foundation of China (No. 61701543) for the financial support.
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