Electrochemical Reduction of CO2at Functionalized Au Electrodes.
Electrochemical reduction of CO2provides an opportunity to store renewable energy as fuels with much greater energy densities than batteries. Product selectivity of the reduction reaction is known to be a function of the electrolyte and electrode; however, electrodes modified with functional ligands may offer new methods to control selectivity. Here, we report the electrochemical reduction of CO2at functionalized Au surfaces with three thiol-tethered ligands: 2-mercaptopropionic acid, 4-pyridinylethanemercaptan, and cysteamine. Remarkably, Au electrodes modified with 4-pyridinylethanemercaptan show a 2-fold increase in Faradaic efficiency and 3-fold increase in formate production relative to Au foil. Conversely, electrodes with 2-mercaptopropionic acid ligands show nearly 100% Faradaic efficiency toward the hydrogen evolution reaction, while cystemine-modified electrodes show 2-fold increases in both CO and H2production. We propose a proton-induced desorption mechanism associated with pKaof the functionalized ligand as responsible for the dramatic selectivity changes.
Gordon and Mary Cain Department of Chemical Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Yuxin
Y
Fang
Gordon and Mary Cain Department of Chemical Engineering, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
John C
0000-0002-9187-3143
JC
Flake