Two silver-containing BEA zeolites prepared by a two-step postsynthesis method (Ag2.0SiBEA) and a conventional wet impregnation (Ag2.0HAlBEA) showed a high activity in the conversion of 1,2-dichloroethane (1,2-DCE) into value added products with 100% selectivity into ethylene and 100% selectivity into vinyl chloride, respectively. The role of the silver in two kinds of studied catalysts was different. The HRTEM, STEM with EDS elemental mapping showed that the excellent activity of silver containing catalyst, prepared by two-step postsynthesis method, in hydrodechlorination of 1,2-DCE was strongly related to the presence of very small (<3 nm) metallic nanoparticles, resistant for the deactivation by chlorine poisoning. On the other hand, introduction of Ag ions into the HAlBEA zeolite led to a decrease of the coke formation during hydrodechlorination process on red-C-Ag2.0HAlBEA zeolite catalyst. As a result, it was observed lower drop of activity of red-C-Ag2.0HAlBEA catalyst than HAlBEA over HDC reaction with maintaining 100% selectivity to vinyl chloride.