Activated hydrogen adsorption on the Pt(100) 1 × 1 surface

Pennemann, B.; Oster, K.; Wandelt, K.

doi:10.1016/0039-6028(91)91116-f

Cited by 19 publications

(4 citation statements)

References 8 publications

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“…27,28 (1 Langmuir corresponds to an exposure of 10 −6 torr during 1 second.) Longer exposures may be necessary to complete the process at still lower temperatures (e.g., >1000 L at 35 K), 29 but it only concerns weakly adsorbed species. The gradual filling of less profitable adsorption sites (atop or two-fold sites, where the hydrogen atoms make fewer contacts with metal atoms) and the increasing role of lateral interactions cause weakening of the Pt−H bonds with hydrogen coverage, especially for metal nanoparticles, where the surface is less ordered.…”

Section: ■ Resultsmentioning

confidence: 99%

“…The hydrogen molecule does not require activation to dissociate on extended Pt surfaces, and the exposure of single crystals and clean metal films to 1–100 Langmuir of H 2 at ∼100 K is usually sufficient to saturate the surface and have the expected H/Pt surf ratio of 1. , (1 Langmuir corresponds to an exposure of 10 –6 torr during 1 second.) Longer exposures may be necessary to complete the process at still lower temperatures (e.g., >1000 L at 35 K), but it only concerns weakly adsorbed species. The gradual filling of less profitable adsorption sites (atop or two-fold sites, where the hydrogen atoms make fewer contacts with metal atoms) and the increasing role of lateral interactions cause weakening of the Pt–H bonds with hydrogen coverage, especially for metal nanoparticles, where the surface is less ordered .…”

Section: Discussionmentioning

confidence: 99%

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Probing the H₂-Induced Restructuring of Pt Nanoclusters by H₂-TPD

Yakovina

Lisitsyn

2016

Langmuir

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Metal clusters with sizes below 1 nm attract great scientific interest, but the main information on their properties still comes from quantum mechanics modeling and costly physical methods of limited availability. We have studied ultradispersed Pt/γ-AlO samples with temperature-programmed desorption (TPD) and complementary adsorption/desorption techniques and observed that the H-TPD profile of Pt/γ-AlO is strongly dependent on the pretreatment conditions (0 < P ≤ 1 bar; 200 K ≤ T ≤ 470 K). The results corroborate recent theoretical and spectroscopic studies predicting alterations in the structure of Pt nanoclusters under H-treatment conditions but reveal that the restructuring needs to overcome continuous activation barriers and leads both to an increase in surface coverage and strengthening of the Pt-H bonds. This was interpreted as being a consequence of the strong interaction of Pt clusters with the support. The results extend insights into the behavior of supported metal particles and expand the potential of existing experimental techniques.

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Section: ■ Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Probing the H₂-Induced Restructuring of Pt Nanoclusters by H₂-TPD

Yakovina

Lisitsyn

2016

Langmuir

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“…It was concluded that the surface migration of H atoms on the Pt surface is remarkably influenced by the effect of quantum tunneling. The hydrogen adsorption of Pt(100) was studied in refs and . Using the LEED, TDS, and work function measurements, however, the direct estimation of the adsorption energy was unavailable. Recently, the authors of ref carried out the combined experimental and theoretical study of the hydrogen TPD spectra on the reconstructed Pt(110) surface.…”

Section: Introductionmentioning

confidence: 99%

“…The studies of hydrogen interaction with the platinum surface, both experimental and theoretical, have a long history − (for the detailed historical assay, see the monograph and references therein). The experimental adsorption energy of H 2 on the Pt(111) surface was obtained using LEED, ELS, TDS, and contact potential experiments.…”

Section: Introductionmentioning

confidence: 99%

Adsorption and Diffusion of Hydrogen on the Surface of the Pt₂₄ Subnanoparticle. A DFT Study

et al. 2016

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Platinum and platinum based materials are of fundamental importance for modern and developed catalysts, fuel cells, sensors, hydrogen production and storage systems, and nanoelectronic devices. The subnanosize cluster Pt24 was considered as a model of the prospective catalytic system based on the oxide and carbide supported Pt nanoparticles (Pt NPs) or Pt NPs with soft spacers anchored to their surface. Structural, electronic, thermodynamic, and spectral properties of the adsorption complexes of molecular and atomic hydrogen on Pt NPs have been studied using the DFT method (the BLYP functional with the 6-31G(p) basis for H and the CRENBS pseudopotential for Pt atoms). On this basis, the adsorption energies for molecular hydrogen at the Pt NPs along with the energies and activation energies of its dissociation were estimated and the pathways of activationless dissociative adsorption were found. The full map of adsorption energies of atomic hydrogen at the various surface regions of Pt24 was obtained. The structures of transition states for the rearrangements between the adsorption complexes were located, and the activation energies for surface migration were calculated. Additionally, several ways of subsurface diffusion of H atoms inside the Pt24 cluster were considered which allows estimating the diffusion parameters and the probability of the hydrogen spillover when the cluster surface is highly covered by ligands restricting the surface migration. The IR and Raman spectra of most favorable adsorption complexes were simulated to provide the possibility of an experimental validation of the results obtained.

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