Decomposition of chlorobenzene over phosphate and sulfate catalysts properties

The catalytic conversion of chlorobenzene (CB) over some metal phosphates and sulfate was studied in the presence of water vapor and oxygen. The conversion of CB proceeded in the order of AlPO4, Zr-3(PO4)(4), CePO4-AlPO4, and La-2(SO3)(3) above 673 K. The major products were CO, CO2, and HCl. The reaction proceeded in the absence of water vapor; however, the activity was greatly reduced in the absence of oxygen. Even in the presence of oxygen, 30 mol % of water vapor inhibited the reaction. No intermediate hydration products were observed. There was no correlation between each of the catalytic activity, the acidity, and the concentration of the surface hydroxys of the catalysts. These results suggest that the essential reaction for CB conversion is oxidation. The specific surface area (SSA) of the catalysts was not changed during the CB conversion.