Center for Excitonics


Proton-Coupled Electron Transfer Processes Underpinning the Production of Renewable Fuels

December 12, 2017 at 4:30pm/36-428

Jillian Dempsey
University of North Carolina/Department of Chemistry

The conversion of energy-poor feedstocks like water and carbon dioxide into energy-rich fuels involves multi-electron, multi-proton transformations. In order to develop catalysts that can mediate fuel production with optimum energy efficiency, this complex proton-electron reactivity must be carefully considered. Using a combination of electrochemical methods and time-resolved spectroscopy, we have revealed new details of how molecular catalysts mediate the reduction of protons to dihydrogen and the experimental parameters that dictate catalyst kinetics. While the energy input to drive endergonic fuel-forming reactions is typically supplied indirectly, such as through electricity produced by a solar photovoltaic, we are also exploring excited-state proton-coupled electron transfer reactions that could directly promote catalysis with visible light. This approach represents an energy-efficient mechanism by which solar energy can be captured and converted to chemical energy. Through these studies, we are revealing opportunities to promote, control and modulate the proton-coupled electron transfer reaction pathways of catalysts.

Jillian Dempsey is an Assistant Professor of Chemistry at the University of North Carolina.  She received her BS from MIT in 2005 and her PhD from California Institute of Technology in 2011.  She was a NSF American Competitiveness in Chemistry Postdoctoral Fellow at the University of Washington, Seattle from 2011-2012.  She received the UNC Junior Faculty Development Award, NSF CAREER Award, and the Packard Fellowship for Science and Engineering in 2015.  In 2016, she was awarded the Air Force Office of Scientific Research Young Investigator Award, and the Sloan Research Fellowship.  Research in Dempsey’s Inorganic Spectroscopy and Solar Energy Conversion group aims to address challenges associated with developing efficient solar energy conversion processes. They are particularly interested in the charge-transfer processes that will ultimately govern efficiency in solar fuel production devices: proton-coupled electron transfer reactions, electron transfer across the interface between a catalyst and semiconductor, and the reduction of protons to hydrogen.