Adsorption and decomposition of methane on gallium oxide films

Citation
D. Kohl et al., Adsorption and decomposition of methane on gallium oxide films, SENS ACTU-B, 59(2-3), 1999, pp. 140-145
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
SENSORS AND ACTUATORS B-CHEMICAL
ISSN journal
0925-4005 → ACNP
Volume
59
Issue
2-3
Year of publication
1999
Pages
140 - 145
Database
ISI
SICI code
0925-4005(19991019)59:2-3<140:AADOMO>2.0.ZU;2-N
Abstract
Surface reactions are investigated by a sensitive mass spectrometer. Ga2O3 films are exposed to square pulses of methane. From the experimental data t he desorption energies and the frequency factors are calculated for H2O and CO2. Semiempirical Hartree-Fock calculations with the Modified Neglect of Diatomic Overlap - Parametric Method 3 (MNDO-PM3) method give information a bout the adsorption process. The energy gain of physisorption amounts to 0. 27 eV. The Heat of Formation (HoF) of the chemisorbed CH3 group and the H a tom is 4.05 eV lower in comparison to the value of the physisorbed methane. After the COlatt, group formation the energy gain is 7.33 eV. The binding energy of the formed COlatt, is calculated to 2.07 eV. The charge transfer is estimated using the Mulliken charges. A reaction scheme for the catalyti c oxidation of methane by lattice oxygen is proposed. (C) 1999 Elsevier Sci ence S.A. All rights reserved.