2809-64-5Relevant articles and documents
Nickel–Tungsten and Nickel–Molybdenum Sulfide Diesel Hydrocarbon Hydrogenation Catalysts Synthesized in Pores of Aromatic Polymer Materials
Batryshin,Makeeva,Kulikov,Kardasheva, Yu. S.,Maksimov,Karakhanov
, p. 575 - 580 (2019/06/24)
Abstract: Porous aromatic polymer materials based on tetraphenylmethane molecules linked by methylene groups have been synthesized. By impregnating these materials with nickel–tungsten and nickel–molybdenum thiosalts, catalysts for the hydrogenation of bicyclic aromatic hydrocarbons of the diesel fraction have been prepared. Nanoparticles of the active sulfide phase are formed in support pores during the reaction; it is assumed that after the formation of the nanoparticles, the support material will undergo partial degradation to rearrange the mesoporous structure into a macroporous structure providing the best diffusion of substrates to the surface of the sulfide nanoparticles. The synthesized catalysts have been tested in the hydrogenation of naphthalene and naphthalene derivatives at a hydrogen pressure of 5 MPa and a temperature of 380°C.
Promoted catalysts for hydrogenation of bicyclic aromatic hydrocarbons obtained in situ from molybdenum and tungsten carbonyls
Zakharyan,Onishchenko,Maksimov
, p. 22 - 31 (2018/02/09)
Promoted Мo and W catalysts have been prepared in situ via thermal decomposition of precursors, oil-soluble salts Mo(CO)6, W(CO)6, С°C16H30O4, and NiC16H30O4. TiO2, Al2O3, and ZrO(NO3)2 · 6H2O have been used as the acidic additives. Also, Mo and W unsupported sulfide catalysts have been prepared in the presence of elemental sulfur as the sulfiding agent. The catalysts have been characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The activity of the catalysts prepared in situ has been evaluated in the hydrogenation reaction of bicyclic aromatic hydrocarbons by the example of model mixtures of 10% solutions of naphthalenes (unsubstituted naphthalene, 1- and 2-methylnaphthalenes, and 1,5- and 2,3-dimethylnaphthalenes) in n-hexadecane. The effect of the precursor/acidic oxide ratio on the activity of the formed catalyst has been found. Hydrogenation of bicyclic aromatic hydrocarbons has been conducted at a hydrogen pressure of 2 and 5 MPa and a temperature of 380 and 400°C for 2 h. Hydrogenation of the unsubstituted aromatic ring has been preferable due to the absence of steric hindrances. The degree of conversion of n-hexadecane under the reaction conditions has been 1.5–7.5% depending on the reaction temperature. It has been found that the activity of the sulfided catalyst in the conversion of 1- and 2-methylnaphthalenes is inferior to the activity of the unsulfided analogue, while partial replacement of TiO2 by Al2O3 results in a decrease in the conversion of the substrates as opposed to the unsulfided catalysts, in which the use of nanocrystalline Al2O3 promotes an increase in the conversion.
Synthesis of tetraline derivatives through depolymerization of polyethers with aromatic compounds using a heterogeneous titanium-exchanged montmorillonite catalyst
Maeno, Zen,Torii, Hiroyuki,Yamada, Shota,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro
, p. 89231 - 89233 (2016/10/03)
A novel depolymerization of poly(tetramethylene glycol) (PTMG) with benzene to tetralin using titanium-exchanged montmorillonite (Ti4+-mont) as a solid acid catalyst is described. This catalyst is applicable to depolymerization of PTMG with some aromatic compounds. This is the first demonstration of the potential use of PTMG as a C4 synthon for organic synthesis.
Synthesis of nickel-tungsten sulfide hydrodearomatization catalysts by the decomposition of oil-soluble precursors
Sizova,Kulikov,Onishchenko,Serdyukov,Maksimov
, p. 44 - 50 (2016/02/03)
Nickel-tungsten sulfide catalysts for the hydrogenation of aromatic hydrocarbons have been prepared by the in situ decomposition of an oil-soluble tungsten hexacarbonyl precursor in a hydrocarbon feedstock using oil-soluble nickel salt nickel(II) 2-ethylhexanoate as a source of nickel. The in situ synthesized Ni-W-S catalyst has been characterized by X-ray photoelectron spectroscopy. The activity of the resulting catalysts has been studied in the hydrogenation of bicyclic aromatic hydrocarbons and dibenzothiophene conversion in a batch reactor at a temperature of 350°C and a hydrogen pressure of 5.0 MPa. It has been shown that the optimum W: Ni molar ratio is 1: 2. Using the example of the hydrofining of feedstock with high sulfur and aromatics contents, it has been shown that the synthesized catalyst exhibits high activity in the hydrogenation of aromatic hydrocarbons.
One-pot synthesis of tetralin derivatives from 3-benzoylpropionic acids: Indium-catalyzed hydrosilylation of ketones and carboxylic acids and intramolecular cyclization
Sakai, Norio,Kobayashi, Taichi,Ogiwara, Yohei
supporting information, p. 1503 - 1505 (2015/11/24)
This reducing system was composed of a small amount (1 mol%) of In(OAc)3, Me2PhSiH, and I2 that effectively catalyzed the hydrosilylation of two different carbonyl groups, a ketone and a carboxylic acid found in 3-benzoylpropionic acids, followed by a subsequent intramolecular cyclization that led to the one-pot preparation of tetralin derivatives.
The hydrogenation of aromatic-naphthalene with Ni2P/CNTs
Ruan, Minzhi,Guan, Jun,He, Demin,Meng, Tao,Zhang, Qiumin
, p. 57700 - 57703 (2015/07/20)
Ni2P/CNTs was synthesized using an impregnation method. XPS revealed that CNTs could affect the electronic properties of bulk Ni2P. The catalyst shows superior activity for HYD of naphthalene with a conversion of 99%, and demonstrates superior tolerance towards potential catalyst poisons, which is higher than Ni/CNTs with a conversion of 89%.
Nickel-tungsten sulfide aromatic hydrocarbon hydrogenation catalysts synthesized in situ in a hydrocarbon medium
Sizova,Serdyukov,Maksimov
, p. 470 - 480 (2015/11/23)
Nickel-tungsten sulfide nanocatalysts for the hydrogenation of aromatic hydrocarbons (HCs) have been prepared by the in situ decomposition of a nickel thiotungstate precursor in a HC feedstock using 1-butyl-1-methylpiperidinium nickel thiotungstate complex [BMPip]2Ni[WS4]2 as the precursor. The in situ synthesized particles have been characterized by X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. It has been shown that the resulting Ni-W-S particles are nanoplates associated in multilayer agglomerates; the average length of the Ni-W-S particles is 6 nm; the average number of layers in the multilayer packaging is three. The catalytic activity of the synthesized catalysts has been studied in the hydrogenation of model mixtures of mono- and bicyclic aromatic HCs and in the conversion of dibenzothiophene in a batch reactor at a temperature of 350°C and a hydrogen pressure of 5.0 MPa. It has been shown that the studied catalysts can be used for the hydrofining of light cycle oil.
Conversion of decalin and 1-methylnaphthalene over AlSBA-15 supported Pt catalysts
Jaroszewska,Masalska,Ba?czkowska,Grzechowiak
, p. 110 - 118 (2013/01/15)
Platinum catalysts (1.5 wt.%) containing AlSBA-15 obtained with various aluminium precursors were tested for activity in 1-methylnaphthalene hydrogenation. Experiments were carried out in a continuous-flow system at atmospheric pressure (240-350 °C, W/F = 0.8 g s/cm3). It was found that 1-methylnaphthalene conversion over Pt-loaded catalysts was not influenced by the aluminium precursor used in the preparation of the Pt/AlSBA-15 catalysts. However, the Pt catalyst prepared with AlSBA-15 obtained from aluminium sulphate provided a higher cis-methyldecalins/trans-methyldecalins ratio in the reaction products as compared to the catalysts obtained with aluminium nitrate or aluminium isopropoxide. Consideration was also given to the influence of platinum amount (0.5, 2.5 and 4.5 wt.%) on the catalytic performance of bifunctional Pt/AlSBA-15 catalysts (AlSBA-15 obtained with aluminium sulphate) in decalin hydroconversion. It was shown that impregnation of AlSBA-15 with H2PtCl6 increased Bronsted acidity. Investigations into decalin conversion were conducted in a continuous-flow system with a fixed-bed reactor (5 MPa, 300-380 °C, H2:CH = 500 N m3/m3; WHSV = 2 h-1). Incorporation of 0.5 wt.% Pt into AlSBA-15 yielded a catalyst with the highest dispersion of the platinum phase and the highest yield of ring opening products, amounting to 26.4 wt.% at 380 °C.
New elements in the gold(I)-catalyzed cycloisomerization of enynyl ester derivatives embedding a cyclohexane template
Harrak, Youssef,Makhlouf, Malika,Azzaro, Stéphane,Mainetti, Emily,Lopez Romero, Juan Manuel,Cariou, Kevin,Gandon, Vincent,Goddard, Jean-Philippe,Malacria, Max,Fensterbank, Louis
experimental part, p. 388 - 399 (2011/02/16)
The gold-catalyzed cycloisomerization of enynyl esters bearing a cyclohexyl template has been studied and has been shown to lead to two types of products arising from 1,2- vs. 1,3-O-acyl-migration. Results have shown to be dependent on the nature of the s
Ring-D aromatic phytosteroids; a model for biogenesis by way of carbon radical rearrangement
Green, Stuart P.,Whiting, Donald A.
, p. 1027 - 1034 (2007/10/03)
A mechanism is postulated for the biogenesis of the unique ring-D aromatic phytosteroids from Nicandra physaloides, which involves rearrangement, ring expansion, and aromatisation of a carbon radical generated by cytochrome P450 (Scheme 1). In support, model hydrindene acids 15b and 18b have been synthesized and subjected to homolytic decarboxylation; the latter acid yielded 6-methyltetralin 24, in biomimetic fashion. The isomeric acid afforded not only 6-methyltetralin 24 but also 5-methyltetralin 26; mechanisms for this unusual rearrangement are discussed.
