Deactivation of a Palladium-Supported Alumina Catalyst by Hydrogen Sulfide during the Oxidation of Methane

Feuerriegel, Uwe; Klose, Wolfgang; Sloboshanin, S.; Goebel, H.; Schaefer, J. A.

doi:10.1021/la00022a032

Cited by 21 publications

(8 citation statements)

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“…(a) Sulfur is the best candidate because (i) it is a well-known poison of noble metals, − (ii) it is present as “inert” sulfate in the support, that is reduced by H 2 to poisonous H 2 S (in air the process does not occur), (iii) very small amounts of S are sufficient to significantly poison the Pd surface (0.2 wt.% is sufficient to form a surface stoichiometry S/Pd surf = 1/1, but a much lower ratio is sufficient to deeply change the Pd surface). This is an important feature because poison must be present in a low amount on the Pd surface, not being detectable by EXAFS.…”

Section: Resultsmentioning

confidence: 99%

Determination of the Particle Size, Available Surface Area, and Nature of Exposed Sites for Silica−Alumina-Supported Pd Nanoparticles: A Multitechnical Approach

et al. 2009

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In this work we used several complementary techniques (TEM, TPR, CO chemisorption, EXAFS and FTIR spectroscopy) to understand the effects of the activation temperature and activation atmosphere (air or H 2 ) on the particle size distribution, the fraction, and the type of exposed surface sites of Pd nanoparticles supported on a high surface area SiO 2 -Al 2 O 3 (SA) support. Pd particle distribution has been carefully determined by a high statistic TEM study, from which the cuboctahedral-like shape of the metal particles is demonstrated. Assuming a model of perfect cuboctahedral particles, from the TEM particle size distribution we estimated the expected average Pd first shell coordination number. This value is slightly larger than that directly found by EXAFS owing to the fraction of very small Pd particles (d < 6-8 Å) that basically escape TEM detection. The same geometrical model allows prediction, from TEM particle size distribution, of the metal dispersion observed by CO chemisorption (S/V Chemi ). The S/V Chemi value drops significantly upon increasing the H 2 -reduction temperature. According to TEM, the sintering process can account only for a very small fraction of the S/V Chemi decrease, suggesting an important poisoning of the potentially available Pd surface. This hypothesis is supported by a parallel experiment of thermal decomposition at the same temperature (in absence of H 2 ), showing a S/V Chemi value almost unchanged. FTIR spectroscopy of adsorbed CO, probing the nature of the Pd surface available for adsorption, confirms the hypothesis.

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Section: Resultsmentioning

confidence: 99%

Determination of the Particle Size, Available Surface Area, and Nature of Exposed Sites for Silica−Alumina-Supported Pd Nanoparticles: A Multitechnical Approach

et al. 2009

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“…The SFG-B fuel gas contained H 2 S, which is of particular concern because it is a known poison for Pd [15][16][17].…”

Section: Resultsmentioning

confidence: 99%

Surface characterization of Pd/Al₂O₃sorbents for mercury capture from fuel gas

Baltrus

Granite

Stanko

et al. 2008

Main Group Chemistry

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The surface composition of a series of Pd/alumina sorbents has been characterized to better understand the factors influencing their ability to adsorb mercury from fuel gas. Both a temperature effect and a dispersion effect were found. Maximum adsorption of Hg occurred at the -lowest temperature tested, 204°C, and decreased with increasing temperatures. Maximum adsorption of Hg on a per-atom basis of Pd is observed at low loadings of Pd ( < S.5% Pd) due to better dispersion of Pd at those loadings; a change in its partitioning occurs at higher loadings. The presence of H2S "in the fuel gas acts to promote the adsorption of Hg through its association with Hg in the Pd lattice.

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“…The partial pressures of the reactants have a crucial impact [35][36][37]. The inhibiting effect of carbon dioxide becomes more visible, when partial pressure of methane is comparably low.…”

Section: Influence Of Carbon Dioxidementioning

confidence: 99%

Removal of oxygen from (bio-)methane via catalytic oxidation of CH 4 —Reaction kinetics for very low O 2 :CH 4 ratios

Ortloff

Bohnau

Graf

et al. 2016

Applied Catalysis B: Environmental

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Deactivation of a Palladium-Supported Alumina Catalyst by Hydrogen Sulfide during the Oxidation of Methane

Cited by 21 publications

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Determination of the Particle Size, Available Surface Area, and Nature of Exposed Sites for Silica−Alumina-Supported Pd Nanoparticles: A Multitechnical Approach

Determination of the Particle Size, Available Surface Area, and Nature of Exposed Sites for Silica−Alumina-Supported Pd Nanoparticles: A Multitechnical Approach

Surface characterization of Pd/Al₂O₃sorbents for mercury capture from fuel gas

Removal of oxygen from (bio-)methane via catalytic oxidation of CH 4 —Reaction kinetics for very low O 2 :CH 4 ratios

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Deactivation of a Palladium-Supported Alumina Catalyst by Hydrogen Sulfide during the Oxidation of Methane

Cited by 21 publications

References 0 publications

Determination of the Particle Size, Available Surface Area, and Nature of Exposed Sites for Silica−Alumina-Supported Pd Nanoparticles: A Multitechnical Approach

Determination of the Particle Size, Available Surface Area, and Nature of Exposed Sites for Silica−Alumina-Supported Pd Nanoparticles: A Multitechnical Approach

Surface characterization of Pd/Al2O3sorbents for mercury capture from fuel gas

Removal of oxygen from (bio-)methane via catalytic oxidation of CH 4 —Reaction kinetics for very low O 2 :CH 4 ratios

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Surface characterization of Pd/Al₂O₃sorbents for mercury capture from fuel gas