J. Phys. Colloques
Volume 47, Numéro C7, Novembre 198633rd International Field Emission Symposium / 33ème Symposium International d'Emission de Champ
|Page(s)||C7-435 - C7-440|
J. Phys. Colloques 47 (1986) C7-435-C7-440
A STUDY OF THE DECOMPOSITION REACTION OF METHANOL OVER Ru FIELD EMITTER SURFACESG.-K. CHUAH, N. KRUSE, G. ABEND et J.H. BLOCK
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-1000 Berlin 33, F.R.G.
The decomposition of methanol on Ru field emitter tips has been studied by pulsed field desorption mass spectrometry in the temperature range from 300 K to 580 K. Various ionic species are detected including the parent molecular ion, CH3OH+, the protonated molecule, CH3OH2+, dehydrogenated species, COHx+ (x = 0...3), CH3+ and RuOyn+ (y = 1...3, n = 1...2). At temperatures below 460 K, high intensities of CH3+ are observed, which correspond to the total oxygen content of RuOyn+. These ions are presumably formed from CH3Oad. For T > 460 K, the intensities of CH3+, COH2+ and RuOyn+ drop while those of COH+ and CO+ increase and reach maxima just at the thermal desorption temperature of CO from Ru. It is concluded that the steady decomposition of methanol below 460 K is prevented by adsorbed CO.