Volatile organic compounds present in air at low concentrations can be oxidized to carbon dioxide and water when exposed to thin films of titania irradiated with near UV light. Borosilicate glass rings were coated with a titania-sol generated by controlled hydrolysis of titanium isopropoxide. A reactant stream containing either 48.99 or 1055 ppm of ethylene was fed continuously to a tubular reactor packed with the coated glass rings and surrounded by blacklight blue fluorescent bulbs. The effluent was analyzed by gas chromatography. Titania supported on glass rings exhibited higher photocatalytic activity than unsupported titania pellets. Preliminary kinetic studies of photocatalytic oxidation of ethylene suggest that the reaction rate can best be described using a Langmuir-Hinshelwood-Hougen-Watson rate expression.