Adsorption of m-xylene

The quantity of aromatic contaminants that adsorb onto TiO2 surfaces is also relatively low. d Hennezel and Ollis [47] measured the dark adsorption of the BTEX compounds at a gas-phase concentration of 50 mg/m . Benzene displays the lowest dark adsorption, followed by ethylbenzene. Higher dark adsorption was observed for toluene and xylenes. At 50 mg/m, the dark adsorption of m-xylene was nearly 10 times that of benzene (Table 1). 

The data on the rate of reaction of o-, m-, and p-xylene over vanadium oxide catalyst and of m-xylene over mixed vanadium oxide catalysts (chromium-vanadium and antimony-vanadium) were correlated with the reaction scheme below by the following rate expressions, which are based on the Langmuir-Hinshelwood mechanisms where the adsorption of m-xylene is strong. 

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