The structure of sulphur adsorption phases on Ni(111) studied by X-ray standing wavefield absorption

Lüdecke, J.; Ettema, A.R.H.F.; Driver, S.M.; Scragg, G.; Kerkar, M.; Woodruff, D.P.; Cowie, Bruce C. C.; Jones, Robert G.; Bastow, Sarah L.

doi:10.1016/0039-6028(96)00822-9

Cited by 30 publications

(12 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the favorable site in the other systems have corresponded with the metal bulk structure. On Ru(0 0 0 1) [4] and Re(0 0 0 1) [5] the S adsorption favors the hcp site while on Ni(1 1 1) [6] and Pt(1 1 1) [8] the fcc site. Based on the DFT results the energy minimum for fcc site is only slightly (0.02 eV) lower than that for the hcp site.…”

Section: Discussionmentioning

confidence: 99%

“…For catalytic purposes the coverage of 1/4 monolayer (ML) is large, but with low energy electron diffraction (LEED) more sparse structures are hard to analyze. The local (2 · 2) adsorption structure have been resolved on Ru(0 0 0 1) [4], Re(0 0 0 1) [5], Ni(1 1 1) [6,7] and Pt(1 1 1) [8]. The earlier results on close-packed transition metal surfaces indicate that on hcp metals the adsorption site is hcp and with fcc metals the site is fcc.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

LEED and DFT investigation on the (2×2)-S overlayer on Co(0001)

Lahtinen¹,

Kantola²,

Jaatinen³

et al. 2005

Surface Science

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

LEED and DFT investigation on the (2×2)-S overlayer on Co(0001)

Lahtinen¹,

Kantola²,

Jaatinen³

et al. 2005

Surface Science

View full text Add to dashboard Cite

“…There is no direct information about the geometry of the adsorbed H 2 S from these experiments to compare with our finding. On Ir(1 1 1) [31], Ni(1 1 1) [32][33][34][35] and Pd(1 1 1) [36][37][38][39][40], previous experimental efforts primarily focused on the sulfidation of the surfaces via room temperature exposure to H 2 S. At this condition, no evidence of molecular adsorption was observed because H 2 S was found to dissociate quickly giving rise to adsorbed S species. To our knowledge, low temperature characterization of H 2 S adsorption on Ir(1 1 1), Ni(1 1 1) and Pd(1 1 1) has never been attempted experimentally.…”

Section: Adsorption Of H 2 S Sh S and H On The Metal Surfacesmentioning

confidence: 99%

“…These efforts have included work on close-packed surfaces of transition (Co(0 0 0 1) [9], Ru(0 0 0 1) [27][28][29][30], Ir(1 1 1) [31], Ni(1 1 1) [32][33][34][35], Pd(1 1 1) [36][37][38][39][40], Pt(1 1 1) [41][42][43][44], Rh(1 1 1) [45][46][47]) and noble metals (Ag(1 1 1) [12,48,49], Au(1 1 1) [50][51][52], Cu(1 1 1) [53][54][55]). The formation of ( p 3 Â p 3) R30°structure on the (1 1 1) surfaces was frequently observed while the (2 Â 2) structure was commonly reported on the (0 0 0 1) face.…”

Section: Introductionmentioning

confidence: 99%

First-principles studies of H2S adsorption and dissociation on metal surfaces

2008

View full text Add to dashboard Cite

Exposure of Pd-based hydrogen purification membranes to H,S. a common contaminant in coal gasification streams, can cause membrane performance to deteriorate, either by deactivating surface sites required for dissociative H, adsorption or by forming a low-permeability sulfide scale. In this work. the composition, structure, and catalytic activity of Pd4S, a surface scale commonly observed in Pd-membrane separation of hydrogen from sulfur-containing gas streams, were examined using a combination of experimental characterization and density functional theory (DFT) calculations. A Pd,S sample was prepared by exposing a 100 f1m Pd foil to H2S at 908 K. Both X-ray photoemission depth profiling and low energy ion scattering spectroscopic (LEISS) analysis reveal slight sulfur-enrichment of the top surface of the sample. This view is consistent with the predictions of DFT atomistic thermodynamic calculations. which identified S-terminated Pd,S surfaces as energetically favored over corresponding Pd-terminated surfaces. Activation barriers for H2 dissociation on the Pd,S surfaces were calculated. Although barriers are higher than on Pd(lll). transition state theory analysis identified reaction pathways on the S-terminated surfaces for which hydrogen dissociation rates are high enough to sustain the separation process at conditions relevant to gasification applications.

show abstract

“…Unlike our PhD measurements, however, SEXAFS does not offer chemical-state specificity, so the measured spectra are some weighted average of the individual SEXAFS from the co-adsorbed S-containing surface species. Atomic S occupies hollow sites on Ni(111) [20] that are significantly closer to the surface than is S in SO 2 , leading to a much-increased S-Ni bond angle relative to the surface normal of ~42°. As a result, the true value of the S-Ni bond angle for the SO 2 species will be smaller than the 'average' value of 35° inferred from the SEXAFS data, by an amount that depends on the relative coverage of atomic S.…”

Section: Somentioning

confidence: 99%

The local structure of SO2 and SO3 on Ni(111): A scanned-energy mode photoelectron diffraction study

et al. 2009

Self Cite

View full text Add to dashboard Cite

O 1s and S 2p scanned-energy mode photoelectron diffraction (PhD) data, combined with multiple-scattering simulations, have been used to determine the local adsorption geometry of the SO 2 and SO 3 species on a Ni(111) surface. For SO 2 , the application of reasonable constraints on the molecular conformation used in the simulations leads to the conclusion that the molecule is centred over hollow sites on the surface, with the molecular plane essentially parallel to the surface, and with both S and O atoms offset from atop sites by almost the same distance of 0.65 Å. For SO 3 , the results are consistent with earlier work which concluded that surface bonding is through the O atoms, with the S atom higher above the surface and the molecular symmetry axis almost perpendicular to the surface. Based on the O 1s PhD data alone, three local adsorption geometries are comparably acceptable, but only one of these is consistent with the results of an earlier normal-incidence X-ray standing wave (NIXSW) study. This optimised structural model differs somewhat from that originally proposed in the NIXSW investigation.

show abstract

The structure of sulphur adsorption phases on Ni(111) studied by X-ray standing wavefield absorption

Cited by 30 publications

References 25 publications

LEED and DFT investigation on the (2×2)-S overlayer on Co(0001)

LEED and DFT investigation on the (2×2)-S overlayer on Co(0001)

First-principles studies of H2S adsorption and dissociation on metal surfaces

The local structure of SO2 and SO3 on Ni(111): A scanned-energy mode photoelectron diffraction study

Contact Info

Product

Resources

About