Heterogeneous photocatalytic decomposition of gas-phase chlorobenzene

Bench-scale laboratory experiments were conducted using broad spectrum UV-A to induce TiO2-based photocatalytic treatment of mono-chlorobenzene under aerobic and anaerobic conditions. Previous photolytic-based studies conducted on chlorinated aromatics support the decomposition pathway of de-halogenation followed by cleavage of the aromatic ring due to attack by OH radicals. However, in this study of anaerobic degradation, GC–MS and HPLC analyses of intermediate by-products accumulated on the catalyst surface indicate that chlorophenols (o-, m-, p-) are the predominant species rather than benzene or phenol, and that dechlorination proceeds after ring cleavage.