Selective Liquid-phase Hydrodechlorination of Chlorotrifluoroethylene over Palladium-Supported Catalysts: Activity and Deactivation

• Published in: Catalysis letters 2010-08, Vol.138 (1-2), p.68-75
• Main Authors: Meng, Bao-Chuan, Sun, Zhao-Yang, Ma, Jin-Peng, Cao, Gui-Ping, Yuan, Wei-Kang
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorbents; Aluminum oxide; Barite; Barium sulfate; Catalysis; Catalysts; Catalytic activity; Chemistry; Chemistry and Materials Science; Chlorotrifluoroethylene; Colloidal state and disperse state; Deactivation; Exact sciences and technology; Functional groups; General and physical chemistry; HNO₃ pretreatment; Hydrodechlorination; Hydrogen; Industrial Chemistry/Chemical Engineering; Leaching; Liquid phases; Organometallic Chemistry; Oxygen atoms; Palladium; Palladium catalysts; Pd/AC catalyst; Physical Chemistry; Porosity; Porous materials; Surface area; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Trifluoroethylene
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-010-0370-8

Liquid-phase hydrodechlorination of chlorotrifluoroethylene (CTFE) to trifluoroethylene (TrFE) with molecular hydrogen was studied over palladium-supported catalysts. BaSO₄, Al₂O₃ and activated carbon (AC) were used as supports, respectively. The results showed that the Pd/AC catalysts exhibit higher activity than Pd/BaSO₄ and Pd/Al₂O₃. The treatment of activated carbon with HNO₃ led to a considerable increase of surface functional groups containing oxygen atoms, which resulted in a higher dispersion of palladium on the supports and enhancement of catalytic activity. The stability of the catalyst was investigated, one reason for the inhibition was the accumulation of NaCl on the surface of Pd/AC that blocks the pores of carbon support. The activity of Pd/AC could partially recovered by washing with water. The other irreversible deactivation of the catalyst are from the change of particle size and the pore structure, leaching of Pd, a decrease of BET surface area and Pd surface area of Pd/AC catalyst. Graphical Abstract [graphic removed]