40458-98-8Relevant articles and documents
The isopropylation of naphthalene over USY zeolite with FAU topology. The selectivities of the products
Sugi, Yoshihiro,Joseph, Stalin,Ramadass, Kavitha,Indirathankam, Sathish Clastinrusselraj,Premkumar, Selvarajan,Dasireddy, Venkata D.B.C.,Yang, Jae-Hun,Al-Muhtaseb, Alaa H.,Liu, Qing,Kubota, Yoshihiro,Komura, Kenichi,Vinu, Ajayan
, p. 606 - 615 (2021/03/31)
The isopropylation of naphthalene (NP) over USY zeolite (FAU06, SiO2/Al2O3 = 6) gave all eight possible diisopropylnaphthalene (DIPN) isomers: β,β- (2,6- and 2,7-), α,β- (1,3-, 1,6-, and 1,7-), and α,α- (1,4- and 1,5-). Th
Method for naphthalene alkylation
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Paragraph 0034-0162, (2018/05/16)
The invention relates to a method for naphthalene alkylation, and mainly solves the problems of poor selectivity and easy deactivation of catalysts in the prior art. The method provided by the invention comprises the following steps: a) mixing a silicon source, an aluminum source, a base, water and a template agent to obtain an initial colloid, and then performing hydrothermal crystallization to obtain a ZSM-5/ZSM-12 composite molecular sieve; b) carrying out ion exchange modification on the prepared composite molecular sieve, and carrying out roasting and silanization modification to obtain anaphthalene alkylation catalyst; and c) applying the obtained naphthalene alkylation catalyst to a naphthalene alkylation reaction. When the naphthalene alkylation catalyst prepared by the method provided by the invention is used to carry out the naphthalene alkylation reaction, the selectivity of 2,6-diisopropylnaphthalene is high, meanwhile, the time when the naphthalene alkylation catalyst gets deactivated is postponed, and a good technical effect is obtained. The technical scheme provided by the invention can be well applied to the naphthalene alkylation reaction.
Production method of diisopropylnaphthalene
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Paragraph 0101-0112, (2017/01/02)
The invention relates to a production method of diisopropylnaphthalene, and mainly solves the problems in the prior art that 2,6-diisopropylnaphthalene is low in selectivity and quick in catalyst deactivation; the catalyst used in the production method is organic silicalite which comprises components in the following mole relationship: (1/n)Al2O3:SiO2:(m/n)R, wherein in the formula n=5-250, m=0.01-50, and R is at least one from alkyl, alkylene or phenyl; the Si29 solid-state NMR (nuclear magnetic resonance) spectroscopy of the organic silicalite at least includes one Si29 nuclear magnetic resonance spectral peak between -80-+50 ppm; the X-ray diffraction pattern of the organic silicalite has the maximum spacing value d at 12.4+/-0.2, 11.0+/-0.3, 9.3+/-0.3, 6.8+/-0.2, 6.1+/-0.2, 5.5+/-0.2, 4.4+/-0.2, 4.0+/-0.2 and 3.4+/-0.1 angstroms, so that the organic silicalite can be used in industrial production of diisopropylnaphthalene.
MOR/SBA-15 Composite Catalysts with Interconnected Meso/Micropores for Improved Activity and Stability in Isopropylation of Naphthalene
Banu, Marimuthu,Lee, Young Hye,Magesh, Ganesan,Nam, Chang-Mo,Lee, Jae Sung
, p. 2354 - 2360 (2015/08/11)
The isopropylation of naphthalene with isopropyl alcohol was studied over composites of MOR/SBA-15 in a high-pressure, fixed-bed reactor. The MOR catalyst showed a high 2,6-/2,7-diisopropyl naphthalene (DIPN) ratio of 1.75, but a low naphthalene conversion (54%) and fast deactivation of the catalyst. The composites of MOR/SBA-15 were prepared by a hydrothermal recrystallization process to obtain hierarchical micro/mesopores. During the process, MOR recrystallized in the mesopores of SBA-15, the structure of which was stabilized by carbon coating formed on the pore walls as a template. The best prepared MOR/SBA-15 catalyst achieved a high conversion of 85%, high stability, and less coking, while maintaining the high 2,6-/2,7-DIPN ratio (≈1.8). The modified micro/mesopore structure allowed facile diffusion of bulky molecules to and from active catalytic sites located in the small MOR pores as a result of the connection between the two types of pores in the MOR/SBA-15 composite. Networking of big and small: To improve naphthalene conversion in isopropylation of naphthalene, a hierarchical meso/micropore structure of zeolite composites is achieved by combining micropores of MOR with mesopores of SBA-15. In the hydrothermal recrystallization process, MOR recrystallizes in the mesopores of SBA-15 stabilized by carbon coating formed on the pore walls as a template.
The isopropylation of naphthalene with propene over H-mordenite: The catalysis at the internal and external acid sites
Sugi, Yoshihiro,Anand, Chokkalingam,Subramaniam, Vishnu Priya,Stalin, Joseph,Choy, Jin-Ho,Cha, Wang Soo,Elzatahry, Ahmed A.,Tamada, Hiroshi,Komura, Kenichi,Vinu, Ajayan
, p. 543 - 552 (2015/02/19)
The isopropylation of naphthalene (NP) with propene over H-Mordenite (MOR) was studied under a wide range of reaction parameters: temperature, propene pressure, period, and NP/MOR ratio. Selective formation of 2,6-diisopropylnaphthalene (2,6-DIPN) was observed at reaction conditions, such as at low reaction temperature, under high propene pressure, and/or with high NP/MOR ratio. However, the decrease in the selectivities for 2,6-DIPN was observed at reaction conditions such as at high temperature, under low propene pressure, and/or with low NP/MOR ratio. The selectivities for 2,6-DIPN in the encapsulated products were remained high and constant under all reaction conditions. These results indicate that the selective formation of 2,6-DIPN occurs through the least bulky transition state due to the exclusion of the bulky isomers by the MOR channels. The decrease in the selectivities for 2,6-DIPN are due to the isomerization of 2,6-DIPN to 2,7-DIPN at the external acid sites, directing towards thermodynamic equilibrium of DIPN isomers.
Isopropylation of naphthalene by isopropanol over conventional and Zn- and Fe-modified USY zeolites
Banu, Marimuthu,Lee, Young Hye,Magesh, Ganesan,Lee, Jae Sung
, p. 120 - 128 (2014/01/06)
Catalytic performances of USY, MOR, and BEA zeolites were compared for the isopropylation of naphthalene by isopropyl alcohol in a high-pressure, fixed-bed reactor. The USY catalyst showed a high conversion of 86% and good stability but a low 2,6-/2,7-DIPN shape selectivity ratio of 0.94. In contrast, over the MOR catalyst, 2,6-DIPN was selectively synthesized with a high 2,6-/2,7-DIPN ratio of 1.75, but low naphthalene conversions and fast deactivation of the catalyst were observed. The USY catalyst was modified by Zn and Fe using the wet impregnation method to enhance the selectivity for 2,6-DIPN. The highest conversion (~95%) and selectivity for 2,6-DIPN (~20%) were achieved with 4% Zn/USY catalyst. It appeared that small metal oxide islands formed in the USY pores to decrease the effective pore size and thus render it mildly shape-selective. Zn loading also decreased the number of strong acid sites responsible for coke formation and increased the number of weak acid sites. The high conversion and stability of Zn-modified catalysts were ascribed to the presence of a suitable admixture of weak and strong acid sites with less coke deposition. The Fe-modified USY catalysts were less effective because the modification increased the number of the strong acid sites.
Shape-selective synthesis of 2,6-diisopropylnaphthalene on H-mordenite catalysts
Brzozowski, Robert,Buijs, Wim
experimental part, p. 181 - 187 (2012/10/07)
To finally dispel any doubts on the shape-selective formation of 2,6-diisopropylnaphthalene (2,6-DIPN) over H-MOR zeolites, naphthalene alkylation was carried out over high-silica H-MOR catalysts with propylene or isopropanol as an alkylating agent and with or without cyclohexane as a solvent. Isomeric composition of DIPN's, determined by one-dimensional GC analysis, was additionally confirmed with advanced two-dimensional GC × GC. Our results proved beyond any doubt shape-selective formation of 2,6-DIPN over these H-MOR catalysts from naphthalene and propylene and without cyclohexane as a solvent. The DIPN mixture contained 60-64% 2,6-DIPN, and the ratio of 2,6-DIPN/2,7-DIPN was in the range 2.5-2.8. We also showed that shape-selective formation of 2,6-DIPN over H-MOR catalyst was depressed by using isopropanol instead of propylene and in the presence of cyclohexane.
Shape-selective isopropylation of aromatic hydrocarbons over h-mordenite in supercritical carbon dioxide medium
Laha, Subhash Chandra,Naiki, Hiroaki,Komura, Kenichi,Sugi, Yoshihiro
supporting information; body text, p. 1283 - 1290 (2012/01/31)
The isopropylation of aromatic hydrocarbons isobutylbenzene (IBB), naphthalene (NP), and biphenyl (BP) was examined over H-mordenite (MOR), H-β (BEA), and H-Y (FAU) zeolites in supercritical carbon dioxide (sc-CO2) medium. MOR was only selective for the formation of the least bulky 4-isobutylcumene (4-IBC) in the isopropylation of IBB. In particular, the catalytic activity and selectivity for 4-IBC were enhanced by the dealumination of MOR; MOR with 110 of SiO2/Al2O3 ratio rendered the highest performance; however, the catalytic activity was decreased by further dealumination. Thermogravimetric analyses confirmed the reduction of coke formation on the catalysts in sc-CO2 medium, preventing the deactivation of MOR. Shape-selective formation of the least bulky isomers, 2,6- diisopropylnaphthalene (2,6-DIPN) and 4,4′-diisopropylbiphenyl (4,4′-DIPB), was also observed in the isopropylation of NP and BP over MOR in sc-CO2. sc-CO2 works as an efficient medium to access and/or replace substrates and their products to/from acidic sites in the MOR channels. In particular, the removal of coke precursors from acidic sites on the zeolite is enhanced by the sc-CO2 medium, resulting in decreased coke formation.
Microwave-assisted regioselective alkylation of naphthalene compounds using alcohols and zeolite catalysts
Yamashita, Hiroshi,Mitsukura, Yumi,Kobashi, Hiroko,Hiroki, Kazuaki,Sugiyama, Jun-ichi,Onishi, Kiyotaka,Sakamoto, Tetsuo
experimental part, p. 145 - 149 (2010/08/20)
Regioselective alkylation of naphthalene compounds with alcohols smoothly proceeded in the presence of zeolite catalysts under microwave irradiation. A H-mordenite (H-M) zeolite catalyst (SiO2/Al2O3 ratio = 240) showed the highest efficiency. In the microwave reactions, high reaction rates and high selectivities for 2,6-dialkylnaphthalenes were achieved. In the best case for the reaction of 2-isopropylnaphthalene with isopropyl alcohol, the conversion and the selectivity were 43.5% and 66.4%, respectively. In di-tert-butylation of naphthalene with tert-butyl alcohol, the conversion and the selectivity reached 86.5% and 70.4%, respectively. The conversions and the selectivities were generally higher than those obtained by conventional oil bath heating.
Alkylation of naphthalene with propylene catalyzed by aluminum chloride immobilized on Al-MCM-41
Tang, Hua,Ji, Min,Wang, Xinkui,He, Min,Cai, Tianxi
experimental part, p. 725 - 728 (2010/12/24)
AlCl3 catalysts immobilized on mesoporous Al-MCM-41 were prepared by a two step vapor method and their catalytic performance was evaluated for the alkylation of naphthalene with propylene in a slurry bubble column reactor. The physico-chemical properties of the supports and catalysts were characterized by X-ray diffraction, N2 adsorption, and pyridine adsorption infrared spectroscopy. The halide loadings of the catalysts were analyzed by a chemical method. For the alkylation of naphthalene with propylene over AlCl3/Al-MCM-41, pore diameters that match the molecular dimensions of 2,6-diisopropylnaphthalene (2,6-DIPN) and an appropriate amount of [-O-AlCl2] in the catalyst are key to controlling activity and selectivity. The AlCl3 catalyst immobilized on mesoporous H/Al-MCM-41 with a Si/Al ratio of 15 exhibited high activity when the alkylation was carried out at 0.1 MPa and 85 °C for 5 h. A naphthalene conversion of 82.1 and a 2,6-DIPN selectivity of 32.2 were obtained.
