Environment-driven reactivity of H2 on PdRu surface alloys

Ramos, M.; Minniti, Marina; Dı́az, Cristina; Farı́as, Daniel; Miranda, Rodolfo; Martín, Fernando; Mártínez, A E; Busnengo, H. F.

doi:10.1039/c3cp52001c

Cited by 16 publications

(25 citation statements)

References 30 publications

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“…To compare with experiments, vibrational state distributions have been computed by thermal averaging normal collision energy resolved results in the limit of normal and total energy scaling. 90 Both limits give almost identical results as vibrational state distributions depend weakly on collision energy, in particular for E proj > 0.1 eV leading to non-negligible cross-sections. Hereafter, we only consider the normal energy scaling limit.…”

Section: B Results and Discussionsupporting

confidence: 51%

Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Pétuya

Larrégaray

Busnengo

et al. 2014

The Journal of Chemical Physics

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Dynamics of the Eley-Rideal (ER) abstraction of H 2 from W(110) is analyzed by means of quasiclassical trajectory calculations. Simulations are based on two different molecule-surface potential energy surfaces (PES) constructed from Density Functional Theory results. One PES is obtained by fitting, using a Flexible Periodic London-Eyring-Polanyi-Sato (FPLEPS) functional form, and the other by interpolation through the corrugation reducing procedure (CRP). Then, the present study allows us to elucidate the ER dynamics sensitivity on the PES representation. Despite some sizable discrepancies between both H+H/W(110) PESs, the obtained projectile-energy dependence of the total ER cross sections are qualitatively very similar ensuring that the main physical ingredients are captured in both PES models. The obtained distributions of the final energy among the different molecular degrees of freedom barely depend on the PES model, being most likely determined by the reaction exothermicity. Therefore, a reasonably good agreement with the measured final vibrational state distribution is observed in spite of the pressure and material gaps between theoretical and experimental conditions.

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Section: B Results and Discussionsupporting

confidence: 51%

Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Pétuya

Larrégaray

Busnengo

et al. 2014

The Journal of Chemical Physics

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“…Such ‘floating back properties’ indicated that surface alloys represented stable surface configurations. [61] Ramos et al [62] investigated the dissociative adsorption of molecular hydrogen on Pd x Ru 1-x /Ru (0001) (0 < x < 1) by means of He atom scattering, DFT and quasi-classical trajectory calculations 62 and found that in a Pd-rich surface alloy the reactivity of Ru atoms in dissociative adsorption of molecular hydrogen was enhanced by the presence of nearest neighbor Pd atoms. However, Pd atoms in the Pd-rich surface alloy were less reactive than the Ru ones regardless of their surroundings because of both electronic and strain effects.…”

Section: Near-surface Alloysmentioning

confidence: 99%

Recent progress in the structure control of Pd–Ru bimetallic nanomaterials

Kusada

Kitagawa

2016

Science and Technology of Advanced Materials

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Pd and Ru are two key elements of the platinum-group metals that are invaluable to areas such as catalysis and energy storage/transfer. To maximize the potential of the Pd and Ru elements, significant effort has been devoted to synthesizing Pd–Ru bimetallic materials. However, most of the reports dealing with this subject describe phase-separated structures such as near-surface alloys and physical mixtures of monometallic nanoparticles (NPs). Pd–Ru alloys with homogenous structure and arbitrary metallic ratio are highly desired for basic scientific research and commercial material design. In the past several years, with the development of nanoscience, Pd–Ru bimetallic alloys with different architectures including heterostructure, core-shell structure and solid-solution alloy were successfully synthesized. In particular, we have now reached the stage of being able to obtain Pd–Ru solid-solution alloy NPs over the whole composition range. These Pd–Ru bimetallic alloys are better catalysts than their parent metal NPs in many catalytic reactions, because the electronic structures of Pd and Ru are modified by alloying. In this review, we describe the recent development in the structure control of Pd–Ru bimetallic nanomaterials. Aiming for a better understanding of the synthesis strategies, some fundamental details including fabrication methods and formation mechanisms are discussed. We stress that the modification of electronic structure, originating from different nanoscale geometry and chemical composition, profoundly affects material properties. Finally, we discuss open issues in this field.

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“…A clever way to do so is the pseudomorphic growth of ultrathin metallic films on top of substrates with different lattice constants. The electronic properties of the stretched (compressed) surface can be substantially modified giving rise to profound changes in the adsorption energetics between strained and unstrained surfaces [13][14][15][16][17][18][19][20]. Hitherto, all the studied systems show that the overall adsorption properties are equally altered, i.e., that the atomic, molecular, and dissociative adsorption are either all improved or all reduced.…”

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confidence: 91%

Surface Strain Improves Molecular Adsorption but Hampers Dissociation forN2on theFe/W(
Goikoetxea
¹
,
Juaristi
²
,
Muiño
³

et al. 2014
Phys. Rev. Lett.
38
6
36
0
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We compare the adsorption dynamics of N 2 on the unstrained Fe(110) and on a 10% expanded Fe monolayer grown on W(110) by performing classical molecular dynamics simulations that use potential energy surfaces calculated with density functional theory. Our results allow us to understand why, experimentally, the molecular adsorption of N 2 is observed on the strained layer but not on Fe(110). Surprisingly, we also find that while surface strain favors the molecular adsorption of N 2 it seems, on the contrary, to impede the dissociative adsorption. This result contrasts with previous examples for which strain is found to modify equally the energetics of chemisorption and dissociation. DOI: 10.1103/PhysRevLett.113.066103 PACS numbers: 68.43.−h, 34.35.+a, 82.20.Kh, 82.65.+r The adsorption of nitrogen on iron surfaces is the standard textbook example when linking basic surface science and industrial heterogeneous catalysis [1]. N 2 adsorption and dissociation is the rate limiting step in ammonia synthesis and iron-based compounds are the preferred solid catalyzers for such a process. It is not a surprise then that extensive research has been devoted to understand and ameliorate the chemistry between N 2 and Fe surfaces [2][3][4][5][6][7][8][9][10]. Chemical properties can be locally altered by several elements, including defects, steps, and/or other adsorbed species. Local strain at the surface has been also shown to change surface reactivity in a significant way [11,12]. However, tuning the adsorption properties in the extended surface is much more involved. A clever way to do so is the pseudomorphic growth of ultrathin metallic films on top of substrates with different lattice constants. The electronic properties of the stretched (compressed) surface can be substantially modified giving rise to profound changes in the adsorption energetics between strained and unstrained surfaces [13][14][15][16][17][18][19][20]. Hitherto, all the studied systems show that the overall adsorption properties are equally altered, i.e., that the atomic, molecular, and dissociative adsorption are either all improved or all reduced.In the particular case of N 2 , it has been experimentally shown that the growth of Fe layers on W(110) strongly enhances the adsorption and dissociation of N 2 as compared with the otherwise fairly unreactive Fe(110) surface [6]. These observations agree with the above mentioned existing understanding of how surface strain affects the overall adsorption properties. However, we show here by means of molecular dynamics simulations that while surface strain favors molecular adsorption due to a uniform reduction of the energy barriers accessing the wells, its effect on the energetics of the dissociation process is surprisingly the opposite and, therefore, the observed atomic N cannot be directly attributed to surface strain in this case. We actually find that the minimum energy barrier to dissociation found in Fe(110) increases by about 500 meV in Fe=Wð110Þ. Interestingly, this energy upshift is not uniformly ...

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Environment-driven reactivity of H2 on PdRu surface alloys

Cited by 16 publications

References 30 publications

Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Recent progress in the structure control of Pd–Ru bimetallic nanomaterials

Surface Strain Improves Molecular Adsorption but Hampers Dissociation forN2on theFe/W(
Goikoetxea
¹
,
Juaristi
²
,
Muiño
³

et al. 2014
Phys. Rev. Lett.
38
6
36
0
View full text Add to dashboard Cite

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Environment-driven reactivity of H2 on PdRu surface alloys

Cited by 16 publications

References 30 publications

Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Dynamics of H2 Eley-Rideal abstraction from W(110): Sensitivity to the representation of the molecule-surface potential

Recent progress in the structure control of Pd–Ru bimetallic nanomaterials

Surface Strain Improves Molecular Adsorption but Hampers Dissociation forN2on theFe/W(Goikoetxea1, Juaristi2, Muiño3 et al. 2014Phys. Rev. Lett.386360View full textAdd to dashboardCite

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Surface Strain Improves Molecular Adsorption but Hampers Dissociation forN2on theFe/W(
Goikoetxea
¹
,
Juaristi
²
,
Muiño
³

et al. 2014
Phys. Rev. Lett.
38
6
36
0
View full text Add to dashboard Cite