C-C bond formation during hydrodechlorination of CCl4 on Pd-containing catalysts.

Ekaterina S. Lokteva, Valery V. Lunin, Elena V. Golubina, Valentina I. Simagina, Marina Egorova, Irina V. Stoyanova

Studies in Surface Science and Catalysis. 12th International Congress on Catalysis, v.130(C), p.1997-2002 (2000)

Abstract. Catalytic transformations of CCl4 in a flow-type system in vapors under 150-230оС in the presence of carbon and titania supported Pd catalysts after special treatment has been studied. Under such conditions not only hydrodechlorination products were formed, but also a mixture of saturated and unsaturated hydrocarbons having chain-length up to C5. The best selectivity in the formation of hydrocarbons C3 was found for the catalysts containing 1 and 4% of Pd: the C3 content was close to 20%. The best selectivity towards C4 hydrocarbons formation (up to 13%) was found for 4% Pd/ "Sibunit". In the presence of 1% Pd/ "Sibunit" the content of ethane in the reaction mixture was higher than that of methane. By means of EM and XPS analysis it was shown, that nano-particles of Pd 15-20 A in size have been formed on the surface of catalysts during preparation, and the size distribution is narrower for the catalysts containing less Pd. Homogeneous active sites formed in this case are active but sensitive to the poisoning by reaction products. Remarkably we haven't found chlorine-containing derivatives of hydrocarbons that had a chain-length more than C1. These facts may be considered as arguments for a consecutive scheme of the reaction (first hydrodechlorination and then olygomerization).

Laboratory of Catalysis and Gas Electrochemistry