Dechlorination of 1,2-dichloroethane catalyzed by Pt-Cu/C: unraveling the role of each metal

The effect of Pt-Cu/C catalyst composition on the activity and selectivity in the reaction of 1,2-dichloroethane dechlorination in a H-2-containing at mosphere has been investigated. For monometallic Pt catalysts and those wit h Cu/Pt atomic ratio less than or equal to 1, the reaction products are alm ost entirely ethane and monochloroethane. However, increasing the Cu/Pt rat io increases the selectivity towards ethylene. Approximately 90% selectivit y towards ethylene is obtained for catalysts with Cu/Pt ratio greater than or equal to 9. Monometallic Cu/C produce only ethylene, but the activity is two orders of magnitude lower than that of other catalysts studied. With t ime on stream during the initial 2-30 h there is a continuous increase in s electivity towards ethylene at the expense of ethane. This behavior was rat ionalized in terms of equilibration of bimetallic particle surface composit ion exposed to the reaction mixture.