TY - JOUR

T1 - Two scenarios of dechlorination of the chlorinated hydrocarbons over nickel-alumina catalyst

AU - Mishakov, Ilya V.

AU - Vedyagin, Aleksey A.

AU - Bauman, Yury I.

AU - Potylitsyna, Arina R.

AU - Kadtsyna, Anastasiya S.

AU - Chesnokov, Vladimir V.

AU - Nalivaiko, Anton Yu

AU - Gromov, Alexander A.

AU - Buyanov, Roman A.

N1 - Funding Information: Funding: This research was funded by the Ministry of Science and Higher Education of the Russian Federation, project numbers AAAA-A17-117041710086-6 and 075-00268-20-02 (ID: 07180-2020-0040). Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/12

Y1 - 2020/12

N2 - 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.

AB - 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.

KW - 1,2-dichloroethane

KW - Carbon nanofibers

KW - Catalytic pyrolysis

KW - Chlorobenzene

KW - Chloroform

KW - Hydrodechlorination

KW - Nickel catalyst

KW - 1,2-DICHLOROETHANE

KW - OXIDE

KW - PERFORMANCE

KW - SELECTIVE HYDRODECHLORINATION

KW - TEMPERATURE-PROGRAMMED-REDUCTION

KW - SOL-GEL CATALYSTS

KW - ETHYLENE

KW - CARBON NANOFIBERS

KW - chlorobenzene

KW - catalytic pyrolysis

KW - DECOMPOSITION

KW - carbon nanofibers

KW - 1

KW - chloroform

KW - nickel catalyst

KW - hydrodechlorination

KW - 2-dichloroethane

KW - DEACTIVATION

UR - http://www.scopus.com/inward/record.url?scp=85098489351&partnerID=8YFLogxK

U2 - 10.3390/catal10121446

DO - 10.3390/catal10121446

M3 - Article

AN - SCOPUS:85098489351

VL - 10

SP - 1

EP - 17

JO - Catalysts

JF - Catalysts

SN - 2073-4344

IS - 12

M1 - 1446

ER -