Hydrogen dissociation on Pt{100}: Nonlinear power law in hydrogen induced restructuring

Using molecular beam sticking probability measurements at desorption temperatures we have made a dynamical measurement of the (1×1) island growth rate and the simultaneous D coverage on the rotated quasihexagonal reconstructed phase (hex-R) during the D-induced hex-R→(1×1) phase transformation on Pt...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:The Journal of chemical physics 1995-08, Vol.103 (6), p.2251-2260
Hauptverfasser: Pasteur, A. T., Dixon-Warren, St. J., King, D. A.
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Using molecular beam sticking probability measurements at desorption temperatures we have made a dynamical measurement of the (1×1) island growth rate and the simultaneous D coverage on the rotated quasihexagonal reconstructed phase (hex-R) during the D-induced hex-R→(1×1) phase transformation on Pt{100}. The island growth rate (rg) is described by a strongly nonlinear power law with respect to the local D coverage on the hex-R phase (θ Dhex) at surface temperatures in the range 150–250 K. The apparent rate is given by rg∝(θ Dhex)4.0±0.5. These kinetics are shown to be consistent with the dependence of the temperature programmed desorption spectra on the surface temperature and rate of D2 impingement during adsorption at ∼245 K. In particular the intensity of the α3 desorption peak is markedly sensitive to these parameters, consistent with its assignment to associative desorption from the (1×1) phase.
ISSN:0021-9606
1089-7690
DOI:10.1063/1.469701