Phase and structure engineering of copper tin heterostructures for efficient electrochemical carbon dioxide reduction.

While engineering the phase and structure of electrocatalysts could regulate the performance of many typical electrochemical processes, its importance to the carbon dioxide electroreduction has been largely unexplored. Herein, a series of phase and structure engineered copper-tin dioxide catalysts have been created and thoroughly exploited for the carbon dioxide electroreduction to correlate performance with their unique structures and phases. The copper oxide/hollow tin dioxide heterostructure catalyst exhibits promising performance, which can tune the products from carbon monoxide to formic acid at high faradaic efficiency by simply changing the electrolysis potentials from -0.7 V to -1.0 V. The excellent performance is attributed to the abundant copper/tin dioxide interfaces involved in the copper oxide/hollow tin dioxide heterostructure during the electrochemical process, decreasing the reaction free-energies for the formation of COOH* species. Our work reported herein emphasizes the importance of phase and structure modulating of catalysts for enhancing electrochemical CO reduction and beyond.