The performance loss and recovery of the fuel cell due to Balance of Plant (BOP) contaminants was identified via a combination of experimental data and a mathematical model. The experiments were designed to study the influence of organic contaminants (e.g. those from BOP materials) on the resistance of the catalyst, ionomer and membrane, and a mathematical model was developed that allowed us to separate these competing resistances from the data collected on an operating fuel cell. For this reason, based on the functional groups, four organic contaminants found in BOP materials, diethylene glycol monoethyl ether (DGMEE), diethylene glycol monoethyl ether acetate (DGMEA), benzyl alcohol (BzOH) and 2,6-diaminotoluene (2,6-DAT) were infused separately to the cathode side of the fuel cell. The cell voltage and high frequency impedance resistance was measured as a function of time. The contaminant feed was then discontinued and voltage recovery was measured. It was determined that compounds with ion exchange properties like 2,6-DAT can cause voltage loss with non-reversible recovery, so this compound was studied in more detail. The degree of voltage loss increased with an increase in concentration, and/or infusion time, and increased with a decrease in catalyst loadings. The major technical challenges for polymer electrolyte membrane fuel cells (PEMFCs) in general are performance, reliability, durability and cost. There is an opportunity to reduce overall system cost by choosing lower cost balance of plant (BOP) materials for PEMFC systems. However, choosing any new system BOP material (e.g., assembly aids, structural plastics, and hoses) without compromising function, fuel cell performance, or life requires understanding the effects of the contaminants that leach from these materials. The contaminants in a fuel cell system originate from the fuel, air, and the different component materials used in construction.Previous studies 1-28 have reported on the effect of contamination on PEMFCs by impurities found in the fuel, fuel-cell components, or the external environment such as carbon monoxide (CO), 8,9 26 It has been demonstrated that even trace amounts of impurities can severely poison the anode, membrane, and cathode, particularly at low-temperature operation.4 These contaminants impact PEMFC performance by hindering kinetics (e.g. CO and H 2 S) or reducing membrane conductivity (e.g. NH 3 and metal cations). 8,18,19 Several models are available that capture kinetic [24][25][26] and ohmic overpotentials [18][19][20]27,28 during the contamination and recovery studies.Although there has been a lot of research on contamination caused by fuel and air side impurities, the effect of contamination originating from system components have only recently been briefly studied.
29-35These results showed that despite the contamination caused by fuel and air side impurities that can effect only the catalyst (e.g., CO) or the membrane (e.g. metal cations), organic contaminants (e.g., those from BOP materials) can have severe effect...