Catalytic conversion of trichloroethylene on nickel containing beta zeolites into value added products

• Reduced NiSiBEA and NiHAlBEA are active catalysts of hydrodechlorination of TCE.
• Ni(0) nanoparticles are responsible for conversion of TCE to value added products.
• Ethylene, propylene and 1,1-dichloroethylene are main products of TCE conversion.
• Activity of studied catalysts depends also on the kind and amount of acidic sites.
• Lewis and Brønsted acidic sites have influence on the activity of studied catalysts.

Nickel containing BEA zeolites, NiSiBEA and NiHAlBEA, with 2 wt% of Ni were prepared by a two-step postsynthesis method and conventional wet impregnation. The calcination of NiSiBEA and NiHAlBEA at 773 K for 3 h in air led to the formation of C-NiSiBEA and C-NiHAlBEA. After reduction at 873 K for 3 h in flowing 10% H2/Ar, red-C-NiSiBEA and red-C-NiHAlBEA were obtained and investigated as the catalysts in hydrodechlorination of trichloroethylene at 503 K. Comparative study performed on red-C-NiSiBEA and red-C-NiHAlBEA showed very high stability of the catalyst prepared by a two-step postsynthesis method and strong deactivation of the catalyst prepared by conventional wet impregnation during ~ 17 h of reaction. Application of both catalysts resulted in high selectivity to unsaturated hydrocarbons that are the most desired products in HDC processes. TPH of the catalysts after kinetic run have shown that the main cause of deactivation of NiHAlBEA is the formation of carbonaceous species during hydrodechlorination of trichloroethylene.

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