Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 2, 2011
Previous Article Next Article

Thermal and photochemical oxidation of self-assembled monolayers on alumina particles exposed to nitrogen dioxide

Author affiliations

Abstract

Alumina is an important component of airborne dust particles as well as of building materials and soils found in the tropospheric boundary layer. While the uptake and reactions of oxides of nitrogen and their photochemistry on alumina have been reported in the past, little is known about the chemistry when organics are also present. Fourier transform infrared (FTIR) spectroscopy at ∼23 °C was used to study reactions of NO2 on γ-Al2O3 particles that had been derivatized using 7-octenyltrichlorosilane to form a self-assembled monolayer (SAM). For comparison, the reactions with untreated γ-Al2O3 were also studied. In both cases, the particles were exposed to water vapor prior to NO2 to provide adsorbed water for reaction. As expected, surface-bound HONO, NO2, and NO3 were formed. Surprisingly, oxidation of the organic by surface-bound nitrogen oxides was observed in the dark, forming organo-nitrogen products identified as nitronates (R2C[double bond, length as m-dash]NO2). Oxidation was more rapid under irradiation (λ > 290 nm) and formed organic nitrates and carbonyl compounds and/or peroxy nitrates in addition to the products observed in the dark. Mass spectrometry of the gas phase during irradiation revealed the production of NO, CO2, and CO. These studies provide evidence for oxidation of organic compounds on particles and boundary layer surfaces that are exposed to air containing oxides of nitrogen, as well as new pathways for the formation of nitrogen-containing compounds on these surfaces.

Graphical abstract: Thermal and photochemical oxidation of self-assembled monolayers on alumina particles exposed to nitrogen dioxide

Back to tab navigation

Article information


Submitted
30 Jun 2010
Accepted
24 Sep 2010
First published
01 Nov 2010

Phys. Chem. Chem. Phys., 2011,13, 604-611
Article type
Paper

Thermal and photochemical oxidation of self-assembled monolayers on alumina particles exposed to nitrogen dioxide

J. D. Raff, J. Szanyi and B. J. Finlayson-Pitts, Phys. Chem. Chem. Phys., 2011, 13, 604
DOI: 10.1039/C0CP01041C

Social activity

Search articles by author

Spotlight

Advertisements