Pd-Ag/SiO2 sol-gel catalysts designed for selective conversion of chlorinated alkanes into alkenes

Aerogel-like Pd-Ag/SiO2 catalysts were prepared in a one-step sol-gel process by using Pd and Ag complexes containing an alkoxide moiety with ensuing ordinary drying under vacuum. Although they are trapped inside microporous silica particles which makes them sinter-proof, the resulting bimetallic particles are completely accessible. The formation of Pd-Ag alloy crystallites allows to obtain a very high selectivity in ethylene during hydrodechlorination of 1,2-dichloroethane to the detriment of ethane which is the main product when pure Pd is used.