A Microelectrode Study of Interfacial Reactions at the Platinum-Alkaline Polymer Interface

• Published in: Journal of the Electrochemical Society Vol. 162; no. 6; pp. F499 - F506
• Main Authors: Yim, Sung-Dae, Chung, Hoon T., Chlistunoff, Jerzy, Kim, Dae-Sik, Fujimoto, Cy, Yang, Tae-Hyun, Kim, Yu Seung
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society 01.01.2015
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/2.0151506jes

Hydrogen oxidation (HOR) and oxygen reduction (ORR) reactions at the platinum/alkaline ionomer interface were investigated using two different alkaline polymer electrolytes, i.e., benzyl-trimethyl ammonium tethered poly(phenylene) (ATM-PP) and phenyl-pentamethyl guanidinium tethered perfluorinated polymer (M-Nafion-FA-TMG). Substantial inhibition of HOR was taking place at the platinum-ATM-PP interface due to the possible cationic group adsorption of ATM-PP, whereas the reaction was virtually unaffected at the platinum-M-Nafion-FA-TMG interface after high anodic potential preconditioning. Moreover, the apparent ORR activity of platinum coated with M-Nafion-FA-TMG was found higher than that in 0.1 M tetra methyl guanidinium solution. In addition, the oxygen permeability of M-Nafion-FA-TMG was found to be ∼2.5 times higher than that of ATM-PP. The above properties of the perfluorinated polymer make it a very promising ionomeric binder for the use in both anode and cathode of alkaline membrane fuel cells.