The effect of phosphine in syngas on Ni–YSZ anode-supported solid oxide fuel cells

Phosphine (PH 3 ) is present at ppm concentrations in coal syngas, a potential fuel source for solid oxide fuel cells (SOFCs). A mass spectrometer is used to monitor fuel mixtures of hydrogen and phosphine after exposure to two environments. In the first environment, the gas mixtures are passed through a heated zone in a tube furnace. In the second environment, the gas mixtures are passed across the anodes of operating SOFCs, both electrolyte-and anode-supported. Phosphine appears to react with residual oxygen in dry hydrogen at intermediate temperatures (400-600 • C) but is stable above 600 • C. Phosphine reacts with water in wet hydrogen mixtures and with a Ni/YSZ anode at temperatures above 400 • C. Evidence is presented for deposition of non-volatile contaminants following prolonged phosphine exposure. The contaminants react with dry hydrogen to generate PH 3 at 800 • C. Mass spectra of the anode exhaust of an electrolyte-supported SOFC show that a few torr of water, either present initially or electrochemically generated by fuel oxidation, is sufficient to suppress the phosphine signal. At all gas compositions and currents, no new mass signals were detected in the mass range of 45-100, suggesting that HPO, HPO 2 and HPO 3 are not products of phosphine reaction or electrochemical oxidation.

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“…As in previous studies, [3][4][5][6][7][8][9][10][11][12][13] this coating yields XRD spectra consistent with nickel phosphide phases.…”

Section: Resultssupporting

confidence: 72%

Mass Spectrometry of SOFC Fuel Mixtures Containing Phosphine

Finklea

Zhang

Jony

et al. 2015

J. Electrochem. Soc.

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“…Each can cause premature degradation of SOFC materials. 6,[9][10][11][12][13][14][15] Many, if not all, of these impurities have been studied extensively using electrochemical methods. Techniques such as electrochemical impedance spectroscopy (EIS) and voltammetry consistently show how exposure to these individual contaminants lead to performance degradation with differing levels of severity and reversibility.…”

mentioning

confidence: 99%

In Operando Vibrational Raman Studies of Chlorine Contamination in Solid Oxide Fuel Cells

Reeping

Walker

2015

J. Electrochem. Soc.

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Vibrational Raman spectroscopy coupled with voltammetry and impedance measurements was used to explore the effects of chlorine on solid oxide fuel cell (SOFC) performance and durability. SOFC anodes were exposed to 110 ppm dry CH 3 Cl at 650 • C for up to four hours while intermittently exposing the cell to methane for ten minute intervals. In these experiments Raman spectroscopy was used to monitor carbon accumulation kinetics. Electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) measurements performed under CH 4 following 1 hour of exposure to CH 3 Cl showed marked degradation. This degradation was less apparent when the SOFC was operated with H 2 in the presence of CH 3 Cl. With methane and CH 3 Cl, peak power diminished at a rate of 14% per hour. Observable carbon accumulation during CH 3 Cl exposure became less pronounced over time. Eventually, carbon formation was suppressed completely suggesting that the primary effect of the Cl contaminant was deactivation of the Ni catalyst with respect to CH bond dissociation. SOFC performance with H 2 in the presence of CH 3 Cl remained largely unchanged. Interestingly, these effects of Cl on SOFC performance with methane proved partially reversible as electrochemical performance and carbon accumulation behavior were recovered upon removal of the CH 3 Cl from the fuel feed. Solid oxide fuel cells are electricity-generating devices capable of fuel-to-electricity conversion efficiencies of more than 80% when combined with heating applications.1-3 These efficiencies far outpace even the most modern fossil fuel fired power plants. 4 In addition, the high operating temperatures of solid oxide fuel cells (SOFCs) allow operation with many different fuels including biogas, syngas, natural gas, gasoline and even some alcohols.5-8 However, this versatility comes at the cost of having to develop SOFC materials capable of withstanding impurities intrinsic to each fuel type. These impurities include, but are not limited to, carbon deposits, sulfur, chlorine, silicon, phosphorus, and mercury. Each can cause premature degradation of SOFC materials.6,9-15 Many, if not all, of these impurities have been studied extensively using electrochemical methods. Techniques such as electrochemical impedance spectroscopy (EIS) and voltammetry consistently show how exposure to these individual contaminants lead to performance degradation with differing levels of severity and reversibility. However, while the electrochemical results quantify overall cell degradation, direct, in-situ evidence of the mechanisms responsible for diminished performance remain speculative. Coupling electrochemical methods with in-situ optical spectroscopy, such as Raman spectroscopy or XPS, advances understanding of the reactions that occur on the SOFC electrode surfaces as well as how those reactions affect performance. Raman spectroscopy has already shown to be a promising technique for high temperature in-situ characterization of molecules on the surface of an SOFC operating on hydrocarbon ...

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“…Besides, the nickel phosphide of Ni 5 P 2 was believed to be produced in a pure hydrogen atmosphere as described by Eq. (2) [23]. It seems the formation of nickel phosphide degrades the cell to a larger extent than that caused by nickel phosphate.…”

Section: Effects Of Ph 3 and Ch 3 CL On Cell Performance At Simulatedmentioning

confidence: 99%

“…It seemed that the presence of PH 3 at a low concentration can unexpectedly cause a larger degradation rate under similar conditions, which may result from effects of the cell dimension or configuration. Xu et al [23] indicated that a constant of 0.46 mV h ±1 degradation in cell voltage was induced by the addition of 10 ppm PH 3 to coal syngas at 800 C. Zhi et al [13] studied the cell performance in a simulated coal-derived gas containing 20 ppm PH 3 at 900 C and their results revealed that sharp degradation occurred after the addition of 20 ppm PH 3…”

Section: Introductionmentioning

confidence: 99%

Effects of PH₃ and CH₃Cl Contaminants on the Performance of Solid Oxide Fuel Cells

Gao

et al. 2014

Fuel Cells

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Solid oxide fuel cells (SOFCs) have been considered as one of the most efficient power generators that can directly convert chemical energy in the natural gas, biomass, or coal‐derived gas to electrical energy. Various contaminants in syngas are capable to cause catalyst malfunction and cell performance drop, limiting fuel cell to a wide application. The effects of PH3 and CH3Cl fuel impurities on the electrochemical performance of SOFCs are investigated at various testing conditions. Performance drop caused by the addition of 10 ppm PH3 remains identical in pure hydrogen and simulated coal‐derived syngas at 750 °C, but a slight increase is observed when the cells are fueled syngas at 850 °C. The presence of CH3Cl in syngas causes cell degradation to a larger extent at 850 °C. Moreover, the cooperative influences of PH3 and CH3Cl impurities in hydrogen are also studied at 750, 800, and 850 °C. The addition of CH3Cl can stop and remove PH3 poisoning behavior, which is associated with each contaminant concentrations and operational temperatures. The related mechanism has been deeply analyzed and diagnosed.

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The effect of phosphine in syngas on Ni–YSZ anode-supported solid oxide fuel cells

Cited by 56 publications

References 17 publications

Mass Spectrometry of SOFC Fuel Mixtures Containing Phosphine

Mass Spectrometry of SOFC Fuel Mixtures Containing Phosphine

In Operando Vibrational Raman Studies of Chlorine Contamination in Solid Oxide Fuel Cells

Effects of PH₃ and CH₃Cl Contaminants on the Performance of Solid Oxide Fuel Cells

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The effect of phosphine in syngas on Ni–YSZ anode-supported solid oxide fuel cells

Cited by 56 publications

References 17 publications

Mass Spectrometry of SOFC Fuel Mixtures Containing Phosphine

Mass Spectrometry of SOFC Fuel Mixtures Containing Phosphine

In Operando Vibrational Raman Studies of Chlorine Contamination in Solid Oxide Fuel Cells

Effects of PH3 and CH3Cl Contaminants on the Performance of Solid Oxide Fuel Cells

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Product

Resources

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Effects of PH₃ and CH₃Cl Contaminants on the Performance of Solid Oxide Fuel Cells