Science
94 Feasibility of Triphos-Ligated Cobalt as an Electrocatalyst for Carbon Dioxide Reduction
Lillee Casselman and Caroline T. Saouma (Chemistry)
Faculty Mentor: Caroline T. Saouma (Chemistry, University of Utah)
In the wake of increasing concern and awareness surrounding global warming, there is a strong push to not only reduce carbon dioxide emissions, but also to advance technologies that negate emissions. One plausible way to do this is through conversion of carbon dioxide to fuels or fuel precursors (carbon monoxide, methanol, formic acid). Very few catalysts can convert carbon dioxide to methanol, one of which is triphos-ligated cobalt; this species has been shown to hydrogenate carbon dioxide to methanol under elevated temperatures and pressures. Knowing that the same catalyst can electrocatalytically reduce protons to hydrogen gas, my project is focused on determining if triphos-ligated cobalt can also serve as an electrocatalyst for carbon dioxide reduction. Using very weak acids, we can circumvent hydrogen gas production at mild potentials, and access a catalytic current that is pronounced in the presence of both carbon dioxide and protons. After synthesizing and characterizing suspected intermediates in the catalytic cycle, my current research efforts have shifted towards controlled-potential electrolysis, and quantifying the resulting products when subjecting the triphos-ligated cobalt and a proton source to a negative potential under carbon dioxide. This work will be contextualized in terms of how carbon dioxide electrocatalysts relate to carbon dioxide hydrogenation catalysts, which may provide strategies for future catalyst designs.