The Contamination Behavior of System Derived Organic Model Compounds on PEMFC Based upon Functional Groups

In this paper, we investigate contamination mechanisms and quantify the effect of organic model compounds aniline, diethyleneglycol monoethyl ether acetate, diethyleneglycol monoethyl ether, 4-methyl benzensulfonamide, benzyl alcohol, and 2,6-diaminotoluene that have been observed to originate from degradation of balance of plant materials on PEMFCs. In situ voltage loss can be quantified by contamination sources such as Pt, the ionomer, and the membrane using isotherm curves that are prepared by ex situ studies considering contamination mechanisms: adsorption on Pt, ion-exchange/absorption in membranes or electrodes. Severe kinetic loss of Pt activity on oxygen reduction reaction was observed for aromatic compounds due to the greater coverage on Pt/C than aliphatic compounds. An ion-exchange reaction by amine-containing aromatic compounds results in significant conductivity losses of the membrane/ionomer, which is main contributor of the performance loss in this study. That is, controlling the voltage losses caused by the membrane/ionomer contamination is critical to ensure the stability of the system. Infusion of non-amine containing compounds into PEMFCs also increased performance loss by an absorption mechanism but reached at steady state with reversible recovery by switching into normal operations without contaminants. (C) 2015 The Electrochemical Society. All rights reserved.