Premium
The Role of Surface Hydrogen Atoms in the Electrochemical Reduction of Pyridine and CO 2 in Aqueous Electrolyte
Author(s) -
Lebègue Estelle,
Agullo Julia,
Morin Mario,
Bélanger Daniel
Publication year - 2014
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201402065
Subject(s) - pyridinium , electrochemistry , glassy carbon , inorganic chemistry , pyridine , chemistry , electrode , reversible hydrogen electrode , electrolyte , adsorption , aqueous solution , hydrogen , cyclic voltammetry , standard hydrogen electrode , working electrode , organic chemistry
Abstract The present study aims to get more insight into the role of pyridinium ions, surface H atoms and the nature of the electrode surface for the electrochemical reduction of CO 2 . The electrochemical activity of pyridinium ions in the absence and presence of CO 2 is investigated on Ir, Pt, Au and glassy carbon electrodes. Glassy carbon and Au electrodes show irreversible reduction of pyridinium characterized by a cathodic peak potential. In the further presence of CO 2 , an increase of the current is noticed and the overall reduction process remains irreversible. In contrast, cyclic voltammograms recorded on an Ir electrode in a pyridine solution under nitrogen and CO 2 are quasi‐reversible and consistent with the participation of H atoms adsorbed onto the electrode surface. Cyclic voltammograms for Ir and Pt electrodes are similar, as expected for metals with a strong affinity for hydrogen. Our results suggest that adsorbed H atoms may play a key role in the electrochemical reduction of CO 2 .