Characterization of sulfur layers from reduced sulfur dioxide on porous platinum black/teflon electrodes

Foral, Michael J.; Langer, Stanley H.

doi:10.1016/0022-0728(88)85060-5

Cited by 40 publications

(40 citation statements)

References 33 publications

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“…At high potential (>1.0 V) (vs. RHE), sulfur adsorbed on Pt begins to be oxidized to sulfate (SO 4 2− ), which desorbs from the Pt surface. This process can be described by the following equation [27]:…”

Section: Resultsmentioning

confidence: 99%

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

Xie

Shao

Zhang

et al. 2012

Electrochimica Acta

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a b s t r a c tA quantitative research on S and SO 2 poisoning Pt/Vulcan carbon (Pt/VC) catalysts for fuel cells was conducted by the three-electrode method. Pt/VC electrodes were contaminated by submersion in a SO 2 -containing solution made up of 0.2 mM Na 2 SO 3 and 0.5 M H 2 SO 4 for different periods of time, and held at 0.05 V (vs. RHE) in 0.5 M H 2 SO 4 solutions in order to gain zero-valence sulfur (S 0 ) poisoned electrodes. The sulfur coverage of Pt was determined from the total charge consumed as the sulfur was oxidized from S 0 at 0.05 V (vs. RHE) to sulfate at >1.1 V (vs. RHE). The summation of initial coverage of S 0 (Â S ) and coverage of H (Â H ) are approximately equal to 1 (Â H + Â S = 1) when 0.5 < Â H < 1, which gives an easy way to figure out the quantity of sulfur adsorbed on Pt/VC. As to SO 2 poisoned Pt/VC, the catalytic activity of oxygen reduction reaction (ORR) decreases linearly with the amount of SO 2 adsorbed on the Pt nanoparticles when 0.45 < Â H < 0.81. When the adsorbed SO 2 was reduced to S 0 , the mass activity was greatly recovered, and the area specific activity was even higher than the unpoisoned Pt/VC.

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Section: Resultsmentioning

confidence: 99%

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

Xie

Shao

Zhang

et al. 2012

Electrochimica Acta

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“…There is disagreement in the literature on the correct adsorption stoichiometry for S on Pt because it is common for a single sulfur atom to poison multiple adjacent Pt sites [2,14,[19][20][21]. The reported adsorption stoichiometries range from 1 to 12 Pt atoms per S atom.…”

Section: Methodsmentioning

confidence: 97%

Deactivation of Pt/VC proton exchange membrane fuel cell cathodes by SO2, H2S and COS

Gould

Батурина

Swider‐Lyons

2009

Journal of Power Sources

103

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“…Catalysis exercised by adsorbed sulphur on Pt was interpreted in terms of preclusion of detrimental SO 2 adsorption, although enhancement by intrinsic sulphur catalysis, i.e. activation of sulphur neighbouring sites through surface electronic interactions, could not be ruled out [10,35]. By contrast, it follows from the discussion in section 3.1 that the oxidation of bulk SO 2 on Au proceeds on a bare surface or at most on a surface with weakly adsorbed SO 2 .…”

Section: Electrocatalysis By Sulphur-modified Gold Electrodesmentioning

confidence: 98%

Electrochemical behaviour of aqueous SO2 at polycrystalline gold electrodes in acidic media. A voltammetric and in-situ vibrational study. Part II. Oxidation of SO2 on bare and sulphur-modified electrodes

Quijada

Morallón

Vázquez

et al. 2001

Electrochimica Acta

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The electrochemical oxidation of SO 2 on polycrystalline gold electrodes has been studied by means of cyclic voltammetry and in situ vibrational techniques. On bare gold electrodes, SO 2 is irreversibly oxidised on forward scans at 0.6 V/RHE, featuring a diffusion-limited peak. Oxidation is inhibited by the formation of chemisorbed oxygen. A SO 2 anodic current rise occurs on the reverse scan in parallel with the reduction of the metal oxide layers. As shown by FT-IR, oxidation proceeds to yield a mixture of soluble S(VI) species as stable reaction products. From vibrational spectra and results from the irreversible adsorption method, it follows that no strongly adsorbed S -O-like residues are present onto the gold surface in the region 0.3-0.5 V/RHE. On sulphur-modified electrodes improved electrocatalysis is manifested by the shift of the diffusion-limited peak to lower potentials. The best performance is observed at a sulphur coverage of 0.5. At higher coverage, sulphur adlayers impart lower catalytic efficiency and eventually show strong poisoning properties. This behaviour is exhibited by sulphur adlayers generated either in situ by SO 2 reduction or ex situ by sulphide adsorption/oxidation in acidic or alkaline media.

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Characterization of sulfur layers from reduced sulfur dioxide on porous platinum black/teflon electrodes

Cited by 40 publications

References 33 publications

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

Deactivation of Pt/VC proton exchange membrane fuel cell cathodes by SO2, H2S and COS

Electrochemical behaviour of aqueous SO2 at polycrystalline gold electrodes in acidic media. A voltammetric and in-situ vibrational study. Part II. Oxidation of SO2 on bare and sulphur-modified electrodes

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