Non-adiabatic reaction pathways in the dissociative adsorption of Oxygen on an Al(111) surface

Dateibereich 10443

2,89 MB in 2 Dateien, zuletzt geändert am 13.02.2013

Dateiliste / Details

DateiDateien geändert amGröße
ABSTRACT.PDF23.01.2002 00:00:0010,6 KB
ThesisBi.pdf23.01.2002 00:00:002,88 MB
In the present work the results of an experimental study on the inital stages of alumi-num oxidation are reported. Despite a long-standing theoretical and experimental effort, this process still presents some puzzling characteristics. Among them, the direct, activated character of the chemi-sorption process: the initial sticking coefficient S 0 is approximately 1% for thermal mole-cules, E i = 0.025 eV, but rises to 90% at E i = 0.9 eV. This findings are at variance with the results of recent density functional theory cal-culations, predicting near unity reaction probability, even at low E i . In an attempt to clar-ify the dynamics of the initial stages of the oxidation process, I investigated the O 2 /Al interaction by means of molecular beam and laser spectrometric techniques (resonantly enhanced multiphoton ionization - REMPI). The results of the present work, coupled to the finding of scanning tunneling microscopy investigations performed by A.J. Komrowski and A.C. Kummel of the University of California, provide compelling evi-dence for the existence of an abstractive pathway for the dissociation of oxygen on alu-minum. The REMPI study also allowed to highlight the dependence of the abstraction coeffi-cient on both the translational and rotational energy of the incoming oxygen molecules.
Lesezeichen:
Permalink | Teilen/Speichern
Dokumententyp:
Wissenschaftliche Abschlussarbeiten » Dissertation
Fakultät / Institut:
Fakultät für Chemie » Physikalische Chemie
Dewey Dezimal-Klassifikation:
500 Naturwissenschaften und Mathematik » 540 Chemie
Stichwörter:
Al(111), Oxygen, oxidation, REMPI, molecular beam, chemisorption, gas-surface dynamics
Beitragender:
Prof. Dr. Hasselbrink, Eckart [Gutachter(in), Rezensent(in)]
Sprache:
Englisch
Kollektion / Status:
Dissertationen / Dokument veröffentlicht
Dokument erstellt am:
03.08.2001
Promotionsantrag am:
07.08.2001
Dateien geändert am:
13.02.2013
Medientyp:
Text