Two Scenarios of Dechlorination of the Chlorinated Hydrocarbons over Nickel-Alumina Catalyst

Catalysts

AntonYu. Nalivaiko¹  AlexanderA. Gromov¹  IlyaV. Mishakov²  ArinaR. Potylitsyna²  YuryI. Bauman²  AlekseyA. Vedyagin²  RomanA. Buyanov²  VladimirV. Chesnokov²  AnastasiyaS. Kadtsyna² 

[1] Catalysis Lab, National University of Science and Technology MISIS, Leninskiy Prospect 4, 119049 Moscow, Russia;Department of Materials Science and Functional Materials, Boreskov Institute of Catalysis SB RAS, Lavrentieva Ave 5, 630090 Novosibirsk, Russia;

关键词: hydrodechlorination;    catalytic pyrolysis;    carbon nanofibers;    nickel catalyst;    1,2-dichloroethane;    chloroform;   

DOI  :  10.3390/catal10121446

来源: DOAJ

【 摘 要 】

Dechlorination processes attract great interest since they are involved in environmental protection and waste disposal technologies. In this paper, the process of gas-phase dechlorination of 1,2-dichloroethane, chloroform, and chlorobenzene over Ni/Al₂O₃ catalyst (90 wt% Ni) prepared by a coprecipitation technique was investigated. The reduction behavior of the oxide precursor NiO/Al₂O₃ was studied by thermogravimetric analysis in a hydrogen medium. A thermodynamic assessment of the conditions under which metallic nickel undergoes deactivation due to the formation of nickel chloride was performed. The dechlorination of chlorinated substrates was studied using a gravimetric flow-through system equipped with McBain balances in a wide range of temperatures (350–650 °C) and hydrogen concentrations (0–98 vol%). The impact of these parameters on selectivity towards the products of hydrodechlorination (C₂H₄, C₂H₆, and C₆H₆) and catalytic pyrolysis (carbon nanomaterial and CH₄) was explored. The relationship between the mechanisms of the catalytic hydrodechlorination and the carbide cycle was discussed, and the specific reaction conditions for the implementation of both scenarios were revealed. According to the electron microscopy data, the carbonaceous products deposited on nickel particles during catalytic pyrolysis are represented by nanofibers with a disordered structure formed due to the peculiarity of the process including the side carbon methanation reaction.

【 授权许可】

Unknown