Poisoning of Pd(100) for the dissociation of H2: a theoretical study of co-adsorption of hydrogen and sulphur

Wilke, S.; Scheffler, Matthias

doi:10.1016/0039-6028(95)00355-x

Cited by 90 publications

(79 citation statements)

References 23 publications

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“…First, we briefly summarize the properties of bulk Pd, the clean Pd(100) suface, and adsorbed hydrogen atoms 29,30 . The calculated lattice constant of Pd calculated by the DFT-GGA is 4.03Å.…”

Section: Resultsmentioning

confidence: 99%

Potential-energy surface forH2dissociation over Pd(100)

1996

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The potential energy surface (PES) of dissociative adsorption of H2 on Pd(100) is investigated using density functional theory and the full-potential linear augmented plane wave (FP-LAPW) method. Several dissociation pathways are identified which have a vanishing energy barrier. A pronounced dependence of the potential energy on "cartwheel" rotations of the molecular axis is found. The calculated PES shows no indication of the presence of a precursor state in front of the surface. Both results indicate that steering effects determine the observed decrease of the sticking coefficient at low energies of the H2 molecules. We show that the topology of the PES is related to the dependence of the covalent H(s)-Pd(d) interactions on the orientation of the H2 molecule.

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Section: Resultsmentioning

confidence: 99%

Potential-energy surface forH2dissociation over Pd(100)

1996

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“…These focused either on the adsorbate induced change of the density of states (DOS) at the Fermi level [43][44][45] or on the adlayer induced electrostatic field [46][47][48]. Just recently, the poisoning of hydrogen dissociation on Pd(100) by sulfur adsorption has been the subject of detailed DFT studies [3,49,50].…”

Section: Dissociative Adsorption At a Sulfur-covered Transition Mmentioning

confidence: 99%

“…In particular in the theoretical description there has been much progress recently due to the improvement of computer power and the development of efficient algorithms. It has become possible to map out detailed potential energy surfaces of the dissociation of hydrogen on metal surfaces by density functional theory calculations [1][2][3][4][5][6][7][8]. The availability of high-dimensional reliable potential energy surfaces has challenged the dynamics community to improve their methods in order to perform high-dimensional dynamical studies on these potentials.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen dissociation on metal surfaces - a model system for reactions on surfaces

Groß¹

1998

Applied Physics A: Materials Science & Processing

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Reactions on surfaces play an important role in many technological applications. Since these processes are often rather complex, one tries to understand single steps of these complicated reactions by investigating simpler system. In particular the hydrogen dissociation on surfaces serves as such a model system. There has been much progress in recent years in the theoretical description of reactions on surfaces by high-dimensional dynamics simulations on potential energy surfaces which are derived from ab initio total energy calculations. In this brief review I will focus on the hydrogen dissociation on the clean and sulfur-covered Pd(100) surface. These calculations established the importance of dynamical concepts like the steering effect. The electronic structure calculations allow furthermore the determination of the factors that determine the reactivity of a particular surface. This will be demonstrated for the poisoning of hydrogen dissociation by sulfur adsorption on the Pd(100) surface. In addition, quantum effects in the dynamics can be assessed by comparing the results of classical with quantum dynamical calculations on the same potential energy surface. 68.35.Ja, 82.20.Kh, 82.65.Pa

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“…Kulprathipanja et al [5] concluded The increase of the activation energy for hydrogen permeation might have been caused by an increase in the energy barrier for hydrogen dissociative adsorption on the Pd/Au alloy surface which was caused by the adsorbed sulfur atoms. Wilke and Scheffler [53] have performed theoretical calculations showing that the hydrogen dissociation path on the Pd surface was non-activated (no activation energy barrier), and would become an activated process when sulfur atoms were adsorbed on Pd surface. …”

Section: Pd/au Membrane Fabrication and Characterizationmentioning

confidence: 99%

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

Hua¹,

Pomerantz²,

Chen³

2008

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The effect of H 2 S poisoning on Pd, Pd/Cu, and Pd/Au alloy composite membranes prepared by the electroless deposition method on porous Inconel supports was investigated to provide a fundamental understanding of the durability and preparation of sulfur tolerant membranes. X-ray photoelectron spectroscopy (XPS) studies showed that the exposure of pure Pd to 50 ppm H 2 S/H 2 mixtures caused bulk sulfide formation at lower temperatures and surface sulfide formation at higher temperatures. Lower temperatures, longer exposure times, and higher H 2 S concentrations resulted in a higher degree of sulfidation. In a Pd membrane, the bulk sulfide formation caused a drastic irrecoverable H 2 permeance decline and an irreparable loss in selectivity.Pd/Cu and Pd/Au alloy membranes exhibited permeance declines due to surface sulfide formation upon exposure to 50 ppm H 2 S/H 2 gas mixtures. However in contrast to the pure Pd membrane, the permeances of the Pd/Cu and Pd/Au alloy membranes were mostly recovered in pure H 2 and the selectivity of the Pd alloy layers remained essentially intact throughout the characterization in H 2 , He and H 2 S/H 2 mixtures which lasted several thousand hours. The amount of irreversible sulfur poisoning decreased with increasing temperature due to the exothermicity of H 2 S adsorption. Longer exposure times increased the amount of irreversible poisoning of the Pd/Cu membrane but not the Pd/Au membrane.Pd/Au coupon studies of the galvanic displacement method showed that higher Au 3+ concentrations, lower pH values, higher bath temperatures and stirring the bath at a rate of 200 rpm yielded faster displacement rates, more uniform depositions, and a higher Au content within the layers. While 400ºC was found to be sufficient to form a Pd/Au alloy

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Poisoning of Pd(100) for the dissociation of H2: a theoretical study of co-adsorption of hydrogen and sulphur

Cited by 90 publications

References 23 publications

Potential-energy surface forH2dissociation over Pd(100)

Potential-energy surface forH2dissociation over Pd(100)

Hydrogen dissociation on metal surfaces - a model system for reactions on surfaces

Sulfur Tolerant Pd/Cu and Pd/Au Alloy Membranes for H2 Separation with High Pressure CO2 for Sequestration

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