(233b) Plasmon-Enhanced Electrochemical Reduction of Carbon Dioxide at a Copper-Silver Cathode
We electrochemically deposited copper nanostructures on a silver foil and coated them with 10 nm of silver to create a plasmonically active cathode. The catalyst was stable for multiple days of electrochemical experiments. Illumination with 365 nm light, close to the plasmon resonance of silver, selectively enhanced some CO2 reduction products while simultaneously suppressing undesired hydrogen evolution. At -1.0 VRHE, ethylene, methane, formate, and products containing three carbons were enhanced upon illumination while the selectivity of carbon monoxide decreased. We investigated the product distribution trends with temperature and found that local heating, a potential plasmonic mechanism, cannot account for the selectivity changes observed in the light. This enhancement of select CO2 reduction products is a promising demonstration of the potential for plasmon-enhanced electrochemical conversion.
This work was largely supported by the National Science Foundation, Grant No. CBET-1653430. Work was primarily performed at the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy, Award No. DE-SC0004993. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy, Contract No. DE-AC02-05CH11231.