Adsorption of ethylene on the Ag() surface

Kokalj, Anton; Corso, Andrea Dal; Gironcoli, Stefano de; Baroni, Stefano

doi:10.1016/s0039-6028(02)01176-7

Cited by 25 publications

(40 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is, in contrast, non-activated on Ag(410): open steps therefore remove the adsorption barrier into such a little distorted state. This result is in qualitative agreement with ab initio calculations showing that ethylene adsorption on Ag(100) is stable only at adatoms [16,17]. On Ag(410), initially, all molecules chemisorb.…”

Section: Introductionsupporting

confidence: 89%

“…Interestingly, the effect becomes larger and more anisotropic at non-zero coverage, where the sticking probability is lowest for molecules impinging at grazing angle to the 100 nanofacet. We believe this to be due again to the relatively small momentum transfer of the molecule upon colliding with an Ag atom, and to the stopping power of the ethylene admolecules, whose adsorption site is at the (100) side of the step according to theory [16]. Molecules impinging at grazing angle to the 110 nanofacet will therefore have a larger chance to hit against already chemisorbed molecules and thus be stopped more efficiently.…”

Section: Resultsmentioning

confidence: 98%

“…For that system, ab initio calculations by Kokalj et al [16] found that the stable adsorption site of C 2 H 4 involves the least coordinated Ag atoms, these being on the (100) terrace close to the step. The saturation coverage on Ag(410) indicates therefore that only non-neighbouring step sites can be populated by admolecules.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Coverage dependence of the dynamics of ethylene adsorption on Ag(210)

Vattuone

Savio

Rocca

2004

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

The sticking probability of C 2 H 4 on Ag (210) is studied by the molecular beam technique and by high resolution electron energy loss spectroscopy. At a crystal temperature of 110 K, adsorption occurs initially into a stable, π-bonded, state. At larger coverage a metastable state is populated, too. The sticking probability, S, decreases with increasing translational energy indicating nonactivated adsorption. At low coverage and for impact angles from −60• to +60• , S is angle independent, decreasing only as soon as the (100) nanofacets start to be shadowed. At higher coverage, in contrast, S depends on the impact angle, decreasing markedly for grazing incidence onto the (100) nanoterraces. The saturation coverage corresponds to quarter occupancy of the available step sites.

show abstract

Section: Introductionsupporting

confidence: 89%

Section: Resultsmentioning

confidence: 98%

See 1 more Smart Citation

Coverage dependence of the dynamics of ethylene adsorption on Ag(210)

Vattuone

Savio

Rocca

2004

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…This In case of ethene which has π orbitals at E f and π * orbital at 6 eV, O ele must possess empty states matching energy range of ethene π. [37] This will facilitate overlap among these orbitals into which π electrons can be transferred. or Ag-5s orbitals, this is contradictory to the presumption that O ele must have significant overlap with Ag-4d or Ag-5s.…”

Section: Resultsmentioning

confidence: 99%

The nature of electrophilic oxygen: Insights from periodic density functional theory investigations

2019

View full text Add to dashboard Cite

Increasing demand of ethylene oxide and the cost of versatile chemical ethene has been a driving force for understanding mechanism of epoxidation to develop highly selective catalytic process.Direct epoxidation is a proposed mechanism which in theory provides 100% selectivity. A key aspect of this mechanism is an electrophilic oxygen (O ele ) species forming on the Ag surface. In the past two and half decades, large number of theoretical and experimental investigations have tried to elucidate formation of O ele on Ag surface with little success. Equipped with this rich literature on Ag-O interactions, we investigate the same using periodic DFT calculations to further understand how silver surface and oxygen interact with each other from a chemical standpoint. Based on energetics, Löwdin charges, topologies and pdos data described in this study, we scrutinize the established notions of O ele . Our study provides no evidence in support of O ele being an atomic species nor a diatomic molecular species. In fact, a triatomic molecular species described in this work bears multiple signatures which are very convincing evidence for considering it as the most sought for electrophilic entity.

show abstract

“…Orbitals were expanded in a plane-wave basis set up to a kinetic energy cut-off of 30 Ry (240 Ry for the charge density cut-off). Densely-packed surfaces were modeled by periodic multi slab model consisting of four atomic layers, with the bottom layer constrained to the bulk positions and the in-plane lattice spacing fixed to the calculated equilibrium bulk lattice parameter: 2.84 A for Fe, 3.67 A for Cu [21], and 4.06 A for Al [22]. All other degrees of freedom were relaxed.…”

Section: Computational Detailsmentioning

confidence: 99%