The PEMFC-integrated CO oxidation — a novel method of simplifying the fuel cell plant

Rohland, B.; Plzak, V.

doi:10.1016/s0378-7753(99)00315-8

Cited by 80 publications

(32 citation statements)

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“…Recently, the preferential oxidation of CO in H 2 has been studied for applications in polymer electrolyte-type fuel cells (PEFCs) to reduce the CO con-centration in the produced fuel gases down to 10 ppm to prevent the fuel cell electrodes from being poisoned [4,5]. The outstanding catalytic activities of Pt, Rh, and Au are widely recognized [6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Formation of subsurface oxygen species and its high activity toward CO oxidation over silver catalysts

Cheng

Huang

et al. 2005

Journal of Catalysis

177

126

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Section: Introductionmentioning

confidence: 99%

Formation of subsurface oxygen species and its high activity toward CO oxidation over silver catalysts

Cheng

Huang

et al. 2005

Journal of Catalysis

177

126

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“…The inlet gas stream fed to the fuel cell must have a very low concentration of CO to avoid poisoning the fuel cell electrode 1,2 . The final selective oxidation step requires a catalyst that is active for the oxidation of CO (reaction R1) in order to reduce the concentration of CO from ~1% to less than 10 ppm in the presence of high concentrations of H 2 , CO 2 , and steam, using a minimum volume of catalyst.…”

Section: Preferential Oxidation (Ncsu)mentioning

confidence: 99%

Reformulation of Coal-Derived Transportation Fuels: Selective Oxidation of Carbon Monoxide on Metal Foam Catalysts

Chin¹,

Sun²,

Roberts³

et al. 2003

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Uses for structured catalytic supports, such as ceramic straight-channel monoliths and ceramic foams, have been established for a long time. One of the most prominent examples is the washcoated ceramic monolith as a three-way catalytic converter for gasoline-powered automobiles. A distinct alternative to the ceramic monolith is the metal foam, with potential use in fuel cell-powered automobiles. The metal foams are characterized by their pores per inch (ppi) and density (ρ).In previous research, using 5 wt% platinum (Pt) and 0.5 wt% iron (Fe) catalysts, washcoated metal foams, 5.08 cm in length and 2.54 cm in diameter, of both varying and similar ppi and ρ were tested for their activity (X CO ) and selectivity (S CO ) on a CO preferential oxidation (PROX) reaction in the presence of a H 2 -rich gas stream. The variances in these metal foams' activity and selectivity were much larger than expected. Other structured supports with 5 wt% Pt, 0-1 wt% Fe weight loading were also examined.A theory for this phenomenon states that even though these structured supports have a similar nominal catalyst weight loading, only a certain percentage of the Pt/Fe catalyst is exposed on the surface as an active site for CO adsorption. We will use two techniques, pulse chemisorption and temperature programmed desorption (TPD), to characterize our structured supports. Active metal count, metal dispersion, and other calculations will help clarify the causes for the activity and selectivity variations between the supports.Results on ceramic monoliths show that a higher Fe loading yields a lower dispersion, potentially because of Fe inhibition of the Pt surface for CO adsorption. This theory is used to explain the reason for activity and selectivity differences for varying ppi and ρ metal foams; less active and selective metal foams have a lower Fe loading, which justifies their higher metal dispersion. Data on the CO desorption temperature and average metal crystallite size for TPD are also collected. iv Clemson AbstractSelective oxidation of CO in hydrogen is an important reaction for producing hydrogen from hydrocarbons suitable for use in fuel cells. Pt has been shown to be very active for this reaction. This paper reports on the results of an investigation into the impact of Fe promotion on Pt/γ-Al 2 O 3 using heavily isotopic transient kinetic analysis (ITKA).In this study, Fe promotion was found to have an impact on activity, selectivity and also time-on-stream behavior of surface reaction parameters. It increased activity and selectivity, as has been also noted by others. ITKA revealed that the higher activity of PtFe is mainly due to an increase in intrinsic site activity when compared to nonpromoted Pt. Fe promotion did not affect significantly the total concentration of active intermediates.In a previous study, Pt/γ-Al 2 O 3 was found to exhibit steady activity for selective CO oxidation after an initial rapid partial deactivation. The PtFe catalyst also showed rapid initial partial deactivation similar to Pt. The act...

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“…yielding the CO tolerance values q i listed in Tab [39] investigated their fuel cell for the susceptibility towards airbleeding by recording the cell voltage at 900 mA/cm 2 using different CO and airbleed levels.…”

Section: Constant Current Densitymentioning

confidence: 99%

Methods for the Quantitative Characterization of the CO Tolerance in a One-Dimensional Polymer Electrolyte Fuel Cell

Gubler

Scherer

Wokaun

2001

Chem. Eng. Technol.

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The use of reformed fuels in polymer electrolyte fuel cells (PEFC) exhibits distinctive advantages over pure hydrogen in terms of fuel supply infrastructure and on‐board fuel storage in a vehicle. Yet small residual CO in the reformate in the order of 10–100 ppm cause severe degradation of fuel cell performance. The CO tolerance of the fuel cell is therefore an important characteristic calling for adequate quantitative evaluation. In this study, we assessed a range of methods to quantify the CO tolerance based on cell polarization data. Generally, no method has the claim to be ideal, but the appropriate choice of CO tolerance quantity rather depends on the design target of the fuel cell system. Analysis of literature data revealed, however, that comparison of fuel cell performance using pure and CO‐contaminated hydrogen, respectively, at constant current density seems to be a popular method, because it yields immediate evidence of anode performance. It was also recognized that CO tolerance manifests on different levels: on the electrocatalyst, the electrode, and the fuel cell level. In order to investigate the CO tolerance on the electrode level, a fuel cell of one‐dimensional construction, like the one used in our experiments, needs to be employed.

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The PEMFC-integrated CO oxidation — a novel method of simplifying the fuel cell plant

Cited by 80 publications

References 0 publications

Formation of subsurface oxygen species and its high activity toward CO oxidation over silver catalysts

Formation of subsurface oxygen species and its high activity toward CO oxidation over silver catalysts

Reformulation of Coal-Derived Transportation Fuels: Selective Oxidation of Carbon Monoxide on Metal Foam Catalysts

Methods for the Quantitative Characterization of the CO Tolerance in a One-Dimensional Polymer Electrolyte Fuel Cell

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