Naru Fukami*, Maina Yosida*, Byung-Dae Lee*, Kazuo Taku** and Masaaki Hosomi*

* Department of Chemical Engineering, Tokyo University of Agriculture and Technology
** Research and Instruments Department, Suido Kiko Company

+ Correspondence should be addressed to Naru Fukami:
(2-24-16 Naka, Koganei-shi, Tokyo 184-8588 Japan)

Abstract

We performed a batch-type photocatalytic decomposition experiment of 1,000 ppm tetrachloroethylene (PCE) gas using a glass vessel inside with its interrorsurface coated by TiO2 in order to elucidate the reaction mechanism in photocatalytic decomposition of PCE in the gas phase. GC/MS and GC/ECD analysis of the reaction intermediates showed that trichloroacetylchloride (TCAC) was mainly produced in the photocatalytic decomposition process. Traceamounts of dichloroacetylchloride (DCAC) and carbon tetrachloride were detected, but detected DCAA and carbon tetrachloride explained only 0.02% and 0.5% of PCE decomposed in the reaction experiment. The extraction of the reaction intermediates in the glass vessel by alkaline solution showed that the final product in this process was hydrogen chloride. Furthermore, it was found that TCAC was easily degraded to hydrogen chloride by photocatalytic decomposition. These results suggest that PCE was transformed to hydrogen chloride via TCAC as an intermediate by photocatalytic decomposition.

Key words: tetrachloroethylene (PCE), gas phase photocatalytic degradation, intermediates, Cl equivalent