Spectroelectrochemical Study of the Role of Pyridinium in Carbon Dioxide Reduction

Wednesday, 27 May 2015: 09:40
PDR 6 (Hilton Chicago)
A. J. Lucio and S. K. Shaw (University of Iowa)
Pyridinium (pyrH+) has been studied for its potential catalytic role in the electrochemical reduction of carbon dioxide (CO2) to methanol. We report electrochemical analysis of the pyrH+ + CO2 interaction on metallic electrodes, independently of the hydrogen evolution reaction. Present results show that gold electrodes exhibit unique pyrH+ and CO2 electrochemistry compared with previous work on platinum electrodes or photochemical systems. Analysis of the electrochemical data show multi-layer adsorption of pyridine, an irreversible reduction wave associated with pyrH+ as the pH approaches the pKa of pyrH+, and a small but significant catalytic activity (0.15 mA/cm2) for CO2 reduction in the presence of pyrH+ at -1.0 V vs. Ag/AgCl.

The present work aims to discern the electroreduction mechanism by analyzing the proposed pyrH+ reduction process in inert purge gas environments using electrochemical and in situ infrared and Raman spectroscopic techniques. This information will guide the analogous exploration under CO2 environments to determine the nature of the enhanced current response. Possible products from the pyrH+ + CO2 electroreduction will be discussed.