Temperature independence of the angle-resolved X-ray photoemission spectra of gold and platinum valence bands

Dabbousi, O.B.; Wehner, P. S.; Shirley, D. A.

doi:10.1016/0038-1098(78)90632-4

Cited by 8 publications

(2 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As was the case with XANES, the XPS valence-band spectrum of bulk Pt exhibits no temperature dependence. 41 Other temperature-dependent studies of the zeolite valence band have been published, 42 but just like the measurements in this work, the statistical quality of the data is not sufficient to make any statements about the temperature dependence of the valence-band spectrum of the zeolite precursor.…”

Section: Resultsmentioning

confidence: 97%

Support and Temperature Effects in Platinum Clusters. 2. Electronic Properties

Boyanov

Morrison

1996

J. Phys. Chem.

View full text Add to dashboard Cite

The effects of Brønsted acidity on the spatial structure and electronic properties of platinum clusters supported on zeolite Y have been examined with X-ray absorption (XANES and EXAFS) and X-ray photoelectron spectroscopy. The clusters contain 10-25 Pt atoms on average, with a nearest-neighbor distance of 2.70 ( 0.01 Å. Static disorder in the atomic distributionswhile certainly present in the supported metalsis shown to be symmetric on average. Increasing Brønsted acidity of the zeolite support has no measurable systematic effect on the spatial structure of the clusters but results in reproducible 5-10% enhancement of near-edge features in the L 2,3 X-ray absorption spectra, as well as 0.2-0.3 eV shifts in Pt 4f and 4d core-level binding energies and valence-band thresholds. Evidence is presented that the interaction between the electronic levels of the cluster and the support is not dominated by charge-transfer effects but results in the creation of unoccupied antibonding states above the Fermi level. Structure of atomic origin isolated from the EXAFS data exhibits no dependence on the measurement temperature and the acidity of the zeolite support. The implications of these results for current XANES-based methods for estimation of valence-band charge count are discussed.

show abstract

Section: Resultsmentioning

confidence: 97%

Support and Temperature Effects in Platinum Clusters. 2. Electronic Properties

Boyanov

Morrison

1996

J. Phys. Chem.

View full text Add to dashboard Cite

show abstract

“…Although initially calculations based upon this approach were also found to qualitatively predict the spectral changes observed in the higher energy regime [37,38], subsequent experimental studies indicated that at these energies a rather complete averaging out over reciprocal space occurs [39,40]. The observation of strong direct transition effects in the low and intermediate energy range, and the full zone averaging that takes place for hν ≈ 10 3 eV, was first explained by Shevchik [41][42][43].…”

Section: The Effect Of Phonon Disordermentioning

confidence: 93%