A study of the main path and of side-reactions upon ethylene oxychlorination over CuCl2-Al2O3 based catalysts

CuCl2/Al2O3 based ethylene oxychlorination catalysts have been characterized by using IR spectroscopy of the surface hydroxy-groups and of adsorbed pyridine and CO2. The ethylene oxychlorination reaction to 1,2-dichloroethane and the dehydrochlorination of ethylchloride (chosen as a probe molecule) have been investigated by using both pulse reactor measurements and in-situ IR experiments in static conditions. Experiments performed over doped alumina and doped CuCl2/Al2O3 confirmed that the exposed support surface can be responsible of the dehydrochlorination of 1,2-dichloroethane (EDC) to vinyl chloride monomer (VCM), with a consequent loss in selectivity in the oxychlorination reactor. Doping alumina with MgCl2 and in particular with KCl limits the activity of the bare support in this side-reaction. \ua9 2000 Elsevier Science B.V. All rights reserved