Photodecomposition of 1,1,2-trichloroethane: spectroscopic evidence for vinyl formation on Pt(111)

• Published in: Surface science Vol. 396; no. 1; pp. 422 - 430
• Main Authors: Hsiao, G.S., Erley, W., Ibach, H.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1998; Amsterdam Elsevier Science; New York, NY
• Subjects: Alkenes; Atomic and molecular physics; Chemistry; Chlorocarbon; Diffuse spectra; predissociation, photodissociation; Electron energy loss spectroscopy; Exact sciences and technology; General and physical chemistry; Low index single crystal surfaces; Molecular properties and interactions with photons; Photochemistry; Photon interactions with molecules; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Physics; Platinum; Surface chemical reaction; Thermal desorption spectroscopy; Alkenes; Low index single crystal surfaces; Platinum; Chlorocarbon; Thermal desorption spectroscopy; Surface chemical reaction; Electron energy loss spectroscopy; Photochemistry; Electron energy loss spectra; TDS; Photochemical reactions; Adsorbed state; Photodissociation; Thermally stimulated desorption; Experimental study
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(97)00697-3

High-resolution electron energy loss spectroscopy (HREELS) and temperature programmed desorption (TPD) were applied to the study of 1,1,2-trichloroethane adsorbed on Pt(111) and its reaction products. Adsorption at 85 K occurred molecularly, as verified by HREELS and TDS measurements. Upon heating, the molecule desorbed intact. Irradiation of the sample with a mercury arc lamp resulted in cleavage of the carbon-chlorine bonds and the formation of a new surface moiety: vinyl. HREELS measurements of both the deuterated and non-deuterated species confirmed this. Vinyl is stable until 450 K. After flashing to higher temperatures a new surface species was formed: chlorocarbyne. This species was no longer observed by 600 K. Throughout the entire heating procedure there was no evidence for the formation of ethylidyne.