A steadily raising amount of carbon dioxide (CO₂) released in atmosphere due to increased consumption of fossil-fuel causes harmful climate change. Additionally, limited reserves of fossil-fuel put a pressure on their future availability thus setting a stage for increased interest in utilizing renewable energy. Electrochemical reduction of CO₂ (CO₂RR) is a promising way to reduce amount of CO₂ as well as generate ‘carbon neutral fuels’ [1]. Among the various CO₂RR products, ethylene (C₂H₄) and ethanol (C₂H₅OH) are of higher energy density and commercially are more valuable than carbon monoxide (CO) and methane (CH₄). Oxide-derived Cu surface is a good candidate for electrochemical CO₂ reduction to C₂H₄ and C₂H₅OH due to its high activity as well as selectivity [2].

Here we report a systematic study of CO₂RR on oxide-derived Cu surface with various oxide thicknesses. The oxide-derived Cu surfaces were prepared via thermal annealing at different temperatures and electrochemical Cu₂O plating on Cu foil. The distribution of the CO₂RR products, such as CO, CH₄, C₂H₄ and C₂H₅OH, as well as the rate of hydrogen evolution reaction are highly dependent on the morphology and thickness of the oxide layer. Thus, we can fine tune the performance of the catalyst via deliberate engineering of the oxide-derived Cu surface, Fig. 1. More detailed discussion on the CO₂RR performance of these catalysts will be presented at the meeting.

Acknowledgements

This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

References

1. Sheng, S. Kattel, S. Yao, B. Yan, Z. Liang, C. J. Hawxhurst, Q. Wu, J.G. Chen, Energy Environ. Sci., 10, 1180 (2017).
2. W. Li, M.W. Kanan, J. Am. Chem. Soc., 17, 134 (2012).