TPD, HREELS and UPS study of the adsorption and reaction of methyl nitrite (CH 3ONO) on Pt(111)

• Published in: Surface science Vol. 410; no. 2; pp. 214 - 227
• Main Authors: Peck, John W, Mahon, Daniel I, Beck, David E, Bansenaur, Barbara, Koel, Bruce E
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-08-1998; Amsterdam Elsevier Science; New York, NY
• Subjects: Auger electron spectroscopy (AES); Chemisorption; Chemistry; Exact sciences and technology; General and physical chemistry; Low energy electron diffraction (LEED); Low index single crystal surfaces; Methylnitrite; Platinum; Solid-gas interface; Surface physical chemistry; Thermal desorption spectroscopy; Visible and ultraviolet photoelectron spectroscopy; Chemisorption; Low energy electron diffraction (LEED); Low index single crystal surfaces; Platinum; Auger electron spectroscopy (AES); Thermal desorption spectroscopy; Visible and ultraviolet photoelectron spectroscopy; Methylnitrite; Gas solid adsorption; Ultraviolet radiation; Surface reaction; Organic adsorbate; Gas solid interface; Metallic adsorbent; Thermodesorption; Photoelectron spectrometry; Experimental study; Electron energy loss spectroscopy
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00284-2

The adsorption and reaction of methyl nitrite (CH
3ONO, CD
3ONO) on Pt(111) was studied using HREELS, UPS, TPD, AES, and LEED. Adsorption of methyl nitrite on Pt(111) at 105
K forms a chemisorbed monolayer with a coverage of 0.25
ML, a physisorbed second layer with the same coverage that desorbs at 134
K, and a condensed multilayer that desorbs at 117
K. The Pt(111) surface is very reactive towards chemisorbed methyl nitrite; adsorption in the monolayer is completely irreversible. CH
3ONO dissociates to form NO and an intermediate which subsequently decomposes to yield CO and H
2 at low coverages and methanol for CH
3ONO coverages above one-half monolayer. We propose that a methoxy intermediate is formed. At least some C–O bond breaking occurs during decomposition to leave carbon on the surface after TPD. UPS and HREELS show that some methyl nitrite decomposition occurs below 110
K and all of the methyl nitrite in the monolayer is decomposed by 165
K. Intermediates from methyl nitrite decomposition are also relatively unstable on the Pt(111) surface since coadsorbed NO, CO and H are formed below 225
K.