The Impact of Operating Conditions on the Performance effect of Selected Airborne PEMFC Contaminants

Journal of Power Sources

2015

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Acetylene is a welding fuel and precursor for organic synthesis, which requires considering it to be a possible air pollutant. In this work, the spatial performance of a proton exchange membrane fuel cell exposed to 300 ppm C 2 H 2 and different operating currents was studied with a segmented cell system. The injection of C 2 H 2 resulted in a cell performance decrease and redistribution of segments' currents depending on the operating conditions. Performance loss was 20-50 mV at 0.1-0.2 A cm −2 and was accompanied by a rapid redistribution of localized currents. Acetylene exposure at 0.4-1.0 A cm −2 led to a sharp voltage decrease to 0.07-0.13 V and significant changes in current distribution during a transition period, when the cell reached a voltage of 0.55-0.6 V. A recovery of the cell voltage was observed after stopping the C 2 H 2 injection. Spatial electrochemical impedance spectroscopy (EIS) data showed different segments' behavior at low and high currents. It was assumed that acetylene oxidation occurs at high cell voltage, while it reduces at low cell potential. A detailed analysis of the current density distribution, its correlation with EIS data and possible C 2 H 2 oxidation/reduction mechanisms are presented and discussed.

mentioning

confidence: 56%

Study of acetylene poisoning of Pt cathode on proton exchange membrane fuel cell spatial performance using a segmented cell system

Reshetenko

Journal of Power Sources

2015

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“…The chosen contaminants belong to different classes of organic substances: alkenes (C3H6), alkynes (C2H2), arenes (C6H6, C10H8), alcohols (i-C3H7OH), nitriles (CH3CN), esters (CH2=C(CH3)COOCH3) and alkyl halides (CH3Br). The selected compounds are widely used as chemical reagents, solvents, welding fuels and pesticides, and they cause negative effects on PEMFC performance [31][32][33][34][35]. According to our studies, these effects are accounted for different mechanisms of interaction between membrane electrode assembly (MEA) components and the contaminants, depending on their chemical nature and properties.…”

Section: Introductionmentioning

confidence: 96%

“…The adsorption of benzene and its derivatives onto Pt has been a subject of fundamental studies due to considerable interest in various electrochemical syntheses involving aromatic hydrocarbons and for the purification of effluent from organic contaminants [42][43][44][45][46][47][48][49][50][51]. However, data concerning the effects of benzene and naphthalene on PEMFC performance and oxygen reduction are rare [15,27,35]. It was shown that even 2 ppm of C6H6 in air caused a fuel cell performance loss of ~150 mV at 1.0 A cm 2 and 80C, whereas exposure to 2 ppm C10H8 resulted in a drastic decrease in cell voltage to 0.1 V under the same conditions.…”

Section: Introductionmentioning

confidence: 99%

Study of the aromatic hydrocarbons poisoning of platinum cathodes on proton exchange membrane fuel cell spatial performance using a segmented cell system

Reshetenko

Journal of Power Sources

2016

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Aromatic hydrocarbons are produced and used in many industrial processes, which makes them hazardous air pollutants. Currently, air is the most convenient oxidant for proton exchange membrane fuel cells (PEMFCs), and air quality is an important consideration because airborne contaminants can negatively affect fuel cell performance. The effects of exposing the cathode of PEMFCs to benzene and naphthalene were investigated using a segmented cell system. The introduction of 2 ppm C6H6 resulted in moderate performance loss of 40-45 mV at 0.2 A cm 2 and 100-110 mV at 1.0 A cm 2 due to benzene adsorption on Pt and its subsequent electrooxidation to CO2 under operating conditions and cell voltages of 0.5-0.8 V. In contrast, PEMFC poisoning by ~2 ppm of naphthalene led to a decrease in cell performance from 0.66 to 0.13 V at 1.0 A cm 2 , which was caused by the strong adsorption of C10H8 onto Pt at cell voltages of 0.2-1.0 V. Naphthalene desorption and hydrogenation only occurred at potentials below 0.2 V. The PEMFCs' performance loss due to each contaminant was recoverable, and the obtained results demonstrated that the fuel cells' exposure to benzene and naphthalene should be limited to concentrations less than 2 ppm.

“…The details of the DOE effort have been described in several publications and have been large in scope identifying seven critical airborne contaminants from an initial list of 260 (2)(3)(4). The DOE sponsored research has focused largely on single contaminants and has identified several important mechanisms for each contaminant that contributes to performance loss (5)(6)(7)(8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

The Effect of Common Airborne Impurities and Mixtures on PEMFC Performance and Durability

Angelo

2014

ECS Trans.

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The effect of exposing the cathode of hydrogen (H 2 ) proton exchange membrane fuel cells (PEMFCs) to the airborne contaminants: sulfur dioxide (SO 2 ), benzene (BZ), and nitrogen dioxide (NO 2 ) on their performance and durability was studied for individual contaminants and mixtures at a total concentration of two parts per million (ppm). The goals were to characterize the effects of contaminant exposure on the: (i) cell performance, (ii) ability of the fuel cell to recover performance using only pure air, (iii) irrecoverable performance loss, and (iv) changes to the durability of the fuel cell as quantified by changes to the electrochemically active surface area (ECSA) of the electrodes. In general, contaminant mixtures decreased performance more than single contaminants. Performance loss was recoverable with pure air when no SO 2 was in the stream and incomplete when it was. Contaminant exposure generally accelerated ECSA loss. IntroductionContaminants present in the air of the oxidant stream of PEMFCs can cause significant performance loss, which can be irreversible in some cases (1). This is an important consideration for developing PEMFCs for commercial applications because airborne contaminants can arise from many different sources including polluted air, geological emissions, and off-gassing from unstable compounds. Thus, the performance of the fuel cell can be affected in unknown ways depending on the quality of the local air (2). It is therefore important to study the effects of contaminants on performance and durability so that the operational lifetime of the PEMFCs can be maximized to facilitate full-scale commercialization and deployment of these devices.The Hawaii Natural Energy Institute (HNEI) is currently researching the performance effects of a number of airborne contaminants and developing strategies to mitigate resulting performance losses through two different projects funded by the United States' Department of Energy (DOE) and the Office of Naval Research (ONR). The details of the DOE effort have been described in several publications and have been large in scope identifying seven critical airborne contaminants from an initial list of 260 (2-4). The DOE sponsored research has focused largely on single contaminants and has identified several important mechanisms for each contaminant that contributes to performance loss ECS Transactions, 64 (3) 773-788 (2014) 773 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.211.208.19 Downloaded on 2015-03-13 to IPThe work presented here is supported by the ONR as part of their goal to deploy fuel cells under a wide range of operating environments including battlefield conditions and regions outside of the United States, which may have poor air quality. The contaminants studied here are SO 2 , NO 2 , and BZ and are different from those in the DOE project to avoid duplicating efforts. Additionally, this work investigates how contaminant mixtures affect performance and durabili...