(617eo) Ionic Compounds for Carbon Dioxide Electroreduction

The electrochemical reduction of carbon dioxide could serve as a carbon neutral source of fuels and chemicals in a sustainable energy economy. For carbon dioxide reduction intermediates which bind to the surface through similar interactions, adsorption energies of the intermediates tend to scale¹. These scaling relations dictate a large overpotential for electrochemical carbon dioxide reduction. Breaking these scaling relations would require selectively stabilizing intermediates. This motivates the exploration of materials beyond metals and metal alloys. We have chosen to first explore metal phosphide and molybdenum sulfide materials. We synthesize the materials using a general methodology of physical vapor deposition of thin metal films, followed by vapor assisted conversion in a tube furnace^2,3. The samples are tested using an electrochemical flow cell previously designed by our group⁴. We characterized the materials before and after electrochemical testing by X-ray photoelectron spectroscopy (XPS) to confirm their identity and observe changes in composition induced during testing. We will report our findings on the activity of these materials for electrochemical carbon dioxide reduction.

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2. Hellstern, T. R., Benck, J. D., Kibsgaard, J., Hahn, C., & Jaramillo, T. F. (2016). Engineering Cobalt Phosphide (CoP) Thin Film Catalysts for Enhanced Hydrogen Evolution Activity on Silicon Photocathodes. Adv. Energy Mater., 6(4), 1â??8.
3. Benck, J. D., Lee, S. C., Fong, K. D., Kibsgaard, J., Sinclair, R., & Jaramillo, T. F. (2014). Designing active and stable silicon photocathodes for solar hydrogen production using molybdenum sulfide nanomaterials. Adv. Energy Mater., 4(18), 1â??8.
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