Active carbon-supported nickel-palladium catalysts for hydrodechlorination of 1,2-dichloroethane and 1,1,2-trichloroethene

Abstract

Norit active carbon-supported Ni-Pd catalysts were prepared, by incipient wetness impregnation, from the metal chlorides NiCl2.6H2O and PdCl2. The catalysts were characterized by temperature-programmed reduction, X-ray diffraction, and scanning electron microscopy, and by temperature-programmed hydrogenation (TPH) of the catalysts after use. When the catalysts were used for gasphase hydrodechlorination (HDC) of 1,2-dichloroethane (1,2-DCA) and 1,1,2-trichloroethene (TCE), very high activity and stability at a relatively low reaction temperature (503 K) were observed. Hydrodechlorination of TCE led to formation of hydrocarbons as the main products. Use of Ni and Ni-Pd catalysts for hydrodechlorination of 1,2-DCA resulted in very high (~100 %) selectivity for ethene. TPH of the catalysts after use for HDC of 1,2-DCA and TCE revealed the presence of carbon and chlorine-containing deposits on the surfaces of the catalysts. Formation of the NiCx fcc phase and the Ni3C hcp carbide phase were detected for the monometallic nickel and Ni95Pd05 catalysts.