Electrochemical CO2 reduction (CO2RR) has the potential to regenerate carbon-based fuels from waste carbon dioxide at ambient temperatures. However, high overpotentials and low selectivity toward a valuable product limits CORR’s commercial viability.
Plasmon-enhanced catalysis has demonstrated the capability to lower the activation barrier and enhance the selectivity of other catalytic reactions such as water splitting and redox reactions of dyes. Our research aims to understand fundamentals underlying plasmon-generated excited charge transfer from voltage-biased cathodes to CO2 reduction intermediates to selectively and efficiently form desirable hydrocarbon products.
We use a custom, front illumination gas flow cell to probe the mechanism of plasmonic PEC CO2 reduction on noble metals nanostructured by lithography. Gaseous and liquid product and photocurrent is measured while varying electrochemical potential, illumination intensity, light wavelength, temperature, and plasmonic catalyst.
We demonstrate that plasmonic photocurrent on voltage-biased silver (Ag) nanopyramid cathodes is selective for CO2 reduction over the competing hydrogen evolution reaction. Our results suggest that further plasmonic enhancements in selectivity and activity towards specific CO2 reduction reactions are possible by tuning the electrode structure and composition.
Bryan D. McCloskey joined the Department of Chemical and Biomolecular Engineering at the University of California, Berkeley in 2014, and holds a joint appointment as Faculty Engineer in the Energy Storage and Distributed Resources Division at Lawrence Berkeley National Laboratory.
His laboratory focuses on characterization of fundamental electrochemical processes to provide guidance for the development of energy storage, electrocatalytic, and corrosion-resistant materials.
He was previously a Research Staff Member (2012-2013) and postdoc (2009-2011) at IBM Almaden Research Center, where he worked on understanding fundamental characteristics of electrochemical processes occurring in Li-O2 batteries. His PhD thesis (2009), supervised by Benny Freeman at the University of Texas at Austin, focused on molecular transport through microporous and dense polymeric membranes, with a particular emphasis on membranes for water purification.
He received his BS (2003) in Chemical Engineering at the Colorado School of Mines where his research, supervised by Drs. Thomas McKinnon and Andrew Herring, focused on employing molecular beam mass spectrometry to characterize aromatic hydrocarbon formation during pyrolysis of cellulosic chars.