The decompositions of dichloromethane, chloroform
tetrachloride, dichloroethylene, chloridetrichloroethylene, and
tetrachloroethylene on Cr2O3/γ-Al2O3 catalyst were
investigated. The major interests of this research were placed
on knowing the conversion and the product distribution of the
decomposition. The effects of water and a second organics in the
feed were investigated. The cause of catalyst deactivation was
also examined. Catalysts were prepared by incipient wetness
impregnation and were characterized by ESCA and AA. The
decomposition reaction was conducted under atmospheric pressure
with a continuous flow tubular reactor. The feeding air
contained 1000 ppm organics. The reaction temperatures were
ranged from 100℃to 500℃. Under the same reaction condition,
the conversions of one -carbon organics decreased in the
following order : CCl4＞CHCl3＞CH2Cl2. The order showed the
conversion was proportional to the number of chlorine atom in
the compound. For organics of 2-carbons, the order was C2H2Cl2＞
C2HCl3＞C2Cl4. The conversion was decreased with the increase in
the number of chlorine atom CO2, HCl, and Cl2 were the major
products form the decomposition. The distribution of the
products was strongly affected by the reaction temperature and
the type of reactants to be decomposed Even though the
conversion of CHCl3 was not effected , the product distribution
was greatly influenced by the presence of water . The water
significantly inhibited the formation of Cl2. In decomposing
CH2Cl2, CHCl3, and CCl4, the rate of Cr2O3/γ-Al2O3 catalyst
deactivaton was in the order : CCl4＞CHCl3＞CH2Cl2. The loss of
Cr2O3 from Cr2O3/γ-Al2O3 was the main cause of catalyst
deactivation.