Selective hydrodechlorination of 1,2-dichloroethane over Pd-Sn/SiO2 catalysts

摘要

Pd/SiO2 and Pd-Sn/SiO2 catalysts prepared by sol-gel processing have been characterised and tested in the selective hydrodechlorination of 1,2-dichloroethane. The obtained solids were characterised by N-2 adsorption at 77 K, H-2 chemisorption, temperature programmed reduction, and X-ray diffraction. It was found that the Pd surface atoms decreases upon the Sn addition, without critical changes on the specific area and reducibility. The turnover frequency increases continuously with the reaction temperature and also as tin loading increases. The selectivity to ethylene is strongly enhanced as temperature increases up to reach almost a constant value of 90%, in the temperature range 500-600 K. It is proposed that Pd-SnOx are the active sites for the selective hydrodechlorination of 1,2-dichloroethane.