Catalytic oxidation of 1,2-dichlorobenzene over V2O5/TiO2-based catalysts

A systematic investigation of the oxidation of 1,2-dichlorobenzene (o-DCB) was conducted over a series of vanadia/titania catalysts with different V2O5 loadings (i.e. 0.8, 3.6 and 5.8 wt%). The TiO2 support was also found to be active for this reaction, but its activity was significantly lower than that of the surface vanadia species. Reaction rates per vanadium atom (i.e. turnover frequencies) were calculated for these catalysts and found to be independent of the vanadia coverage. Kinetic measurements showed that under excess oxygen conditions, the reaction is approximately first order in o-DCB and zero order in oxygen. Carbon monoxide and carbon dioxide were the only products detected. The selectivity towards CO was approximately 40-45% and was found to be independent of vanadia loading and temperature. No deactivation of the catalyst was observed even after 100 h of operation at 723 K. Addition of WO3, MoO3 and ZnO to the V2O5/TiO2 system was found to have no significant effect on its activity for o-DCB oxidation. (C) 1998 Elsevier Science B.V.