In situ FTIR study on photo-catalytic degradation of trichloroethylene over TiO₂

Photo-degradation and gas-phase photocatalytic degradation on TiO2of trichloroethy-lene were stu-died by in situ infrared spectroscopy. The results show that UV/TiO2has a higher degradation capacity than UV on trichloroethylene. In the photocatalytic degradation process, dichloroacetyl chloride, carbon dioxide, carbon monoxide, water, hydrogen chloride and phosgene were detected. Base on the in situ FTIR spectra in different stages, the reaction mechanism of trichloroethylene photocatalysis on TiO2was proposed: trichloroethylene was oxidized by hydroxyl radical and other free radical and formed to dichloroacetyl chloride. Finally, dichloroacetyl chloride was converted further to carbon dioxide, carbon monoxide, water, hydrogen chloride and phosgene.