3877-19-8Relevant academic research and scientific papers
A new precursor for synthesis of nickel-tungsten sulfide aromatic hydrogenation catalyst
Serdyukov,Kniazeva,Sizova,Zubavichus,Dorovatovskii,Maximov
, (2021/01/18)
The unsupported NiWS-catalyst was obtained from the precursor [Ph3S]2Ni(WS4)2 in a hydrocarbon medium (in situ) for hydrogenation bicyclic aromatic compounds. The precursor [Ph3S]2Ni(WS4)2 and the catalyst prepared on its basis were studied by the X-ray diffraction and X-ray absorption methods, XPS and TEM. It was found that the new catalyst formed in situ contains tungsten sulfide and nickel sulfide nanophases. Tungsten sulfide, which has a layered structure, partially forms an insertion compound with nickel that enters between the WS2 layers and bonds covalently to sulfur. The proposed catalyst has proved to be active in the hydrodearomatization processes of model aromatic compounds (naphthalene, methylnaphthalenes) and exhibited the maximum selectivity with the formation of decalins compared to other earlier studied catalysts formed from other precursors in the reaction medium.
Synthesis of renewable alkylated naphthalenes with benzaldehyde and angelica lactone
Cong, Yu,Li, Guangyi,Li, Ning,Wang, Aiqin,Wang, Ran,Wang, Xiaodong,Xu, Jilei,Zhang, Tao
supporting information, p. 5474 - 5480 (2021/08/16)
Herein, we report a new route for the synthesis of renewable alkylated naphthalenes (ANs) with benzaldehyde and angelica lactone, two platform compounds that can be derived from lignocellulose.
Hydroconversion of 2-methylnaphtalene and dibenzothiophene over sulfide catalysts in the presence of water under CO pressure
Glotov, A. P.,Karakhanov, E. A.,Maximov, A. L.,Vutolkina, A. V.
, p. 280 - 288 (2020/04/17)
Unsupported highly dispersed nanosized catalysts based on transition metal sulfides were prepared insitu, in water-oil emulsions, by high-temperature decomposition of oil soluble metal precursors using elemental sulfur as sulfiding agent. Their catalytic activity was tested in hydroconversion of 2-methylnaphtalene and dibenzothiophene at 380 °C under H2 pressure of 5 MPa. In addition, the catalysts were tested in the same reactions in the CO?H2O medium (p(CO) = 5 MPa, the CO: H2O molar ratio was 2: 1, ω(H2O) = 20 wt.%) in which hydrogen is formed through a water gas shift reaction (WGSR). Unsupported Ni?Mo-sulfide catalysts were found to be the most active compared to catalysts supported on alumina. Transmission electron microscopy served to investigate the structure and determine general geometric characteristics of Ni?Mo?S particles formed in toluene—water medium by decomposition of transition metal naphthenates and hexacarbonyls in the presence of elemental sulfur under CO pressure. The method described in this study enables one to synthesize nanosized catalysts with a high content of active sulfide phase.
Effect of Composition of Cobalt-Molybdenum-Containing Sulfonium Thiosalts on the Hydrogenation Activity of Nanosized Catalysts In Situ Synthesized on Their Basis
Knyazeva,Panyukova,Kuchinskaya,Kulikov,Maximov
, p. 1285 - 1292 (2019/12/28)
Abstract: Cobalt-molybdenum-containing thiosalts with different composition of the sulfonium cation are prepared. The activities of sulfide catalysts in situ synthesized on their basis in the hydrogenation of substituted naphthalenes are compared. It is shown that the sulfonium cation composition affects the morphology of the sulfide particles and the phase composition of the catalyst. It is demonstrated that the conversion of model alkyl-substituted bicyclic aromatic hydrocarbons is higher in the presence of the catalyst prepared from the phenylsulfonium thiosalt.
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.
Hydrogenation of Aromatic Substrates over Dispersed Ni–Mo Sulfide Catalysts in System H2O/CO
Vutolkina,Makhmutov,Zanina,Maximov,Glotov,Sinikova,Karakhanov
, p. 528 - 534 (2018/07/29)
The activity of unsupported Ni–Mo sulfide catalysts formed during the in situ decomposition of oil-soluble precursors (molybdenum hexacarbonyl, nickel naphthenate) in the hydrogenation of aromatic and naphthene-aromatic compounds is studied. The catalysts are characterized by HRTEM and XPS. Catalytic experiments are conducted at temperatures of 340–380°C and an increased pressure of ?? in the presence of water providing the in situ generation of hydrogen via the water-gas shift reaction. The catalysts exhibit a high activity in the hydrogenation of model substrates (methyl- and dimethyl-substituted naphthalenes and anthracene).
Hydrodearomatization catalysts based on molybdenum hexacarbonyl Mo(CO)6 supported on mesoporous aromatic frameworks
Maksimov,Karakhanov,Kulikov,Terenina
, p. 589 - 594 (2017/07/22)
A method for synthesizing fine hydrodearomatization catalysts based on the immobilization of molybdenum carbonyl into the pores of mesoporous aromatic frameworks is proposed. It is shown that the amount of the deposited metal and the average size of the resulting particles depend on the support and the deposition method characteristics. The catalytic activity of the synthesized materials in the hydrogenation of bicyclic hydrocarbons at a hydrogen pressure of 5.0 MPa in a temperature range of 330–500°C is studied using the example of naphthalene, methylnaphthalenes, and biphenyl as model substrates.
Alkyl-Aryl Coupling Catalyzed by Tandem Systems of Pincer-Ligated Iridium Complexes and Zeolites
Dinh, Long V.,Li, Bo,Kumar, Akshai,Schinski, William,Field, Kathleen D.,Kuperman, Alexander,Celik, Fuat E.,Goldman, Alan S.
, p. 2836 - 2841 (2016/07/06)
We report that pincer-ligated iridium catalysts for alkane dehydrogenation can operate in tandem with zeolite catalysts for arene-alkene coupling, to effect the overall intramolecular dehydrocoupling of alkyl-H and aryl-H bonds (i.e., the dehydrocyclization of alkyl benzene). Thus, zeolite and soluble iridium cocatalysts in refluxing pentylbenzene (205 °C) gave high yields of 1-methyl-1,2,3,4-tetrahydronaphthalene. Subsequent dehydrogenation and isomerization affords 1- and 2-methylnaphthalene and 2-methyl-1,2,3,4-tetrahydronaphthalene. Total yields of cyclized product as high as 5.4 M (94%) have been obtained, corresponding to 6800 turnovers per mol Ir. Turnover numbers for the tandem-catalyzed dehydrocyclization are much greater than those obtained for simple dehydrogenation by Ir catalysts (to give olefins) in the absence of zeolite.
Selective hydroconversion of naphthalenes into light alkyl-aromatic hydrocarbons
Choi, Yeseul,Lee, Jihye,Shin, Jaeuk,Lee, Seulah,Kim, Donguk,Lee, Jung Kyoo
, p. 140 - 150 (2015/05/05)
2-Ring aromatics such as naphthalene and alkyl-naphthalenes constitute a high fraction in the diesel boiling point range by-products from oil refining and petrochemical plants. A two-step catalytic process, consisting of a selective hydrogenation of naphthalenes to tetralins and a subsequent hydrocracking of tetralins into light alkyl-aromatic hydrocarbons rich in BTX (benzene, toluene, xylenes), was postulated and studied in a fixed bed down-flow reactor under a moderate pressure of 3-4 MPa. For the selective hydrogenation of naphthalenes to tetralins, it was found that the catalytic performances of Mo2C-supported catalysts were superior in terms of tetralins yield as well as selectivity to the conventional metal-supported catalysts such as Pt, Co, Ni and NiW supported catalysts. The hydrocracking of tetralin was demonstrated to produce light alkyl-aromatic hydrocarbons rich in BTX over a monofunctional H-Beta and a bifunctional Ni/H-Beta catalyst. For the high per pass yield of BTX in the hydrocracking of tetralin in which chemical equilibrium limits its conversion and product selectivity, the bifunctional Ni/H-Beta catalyst was found to be highly promising compared with the monofunctional H-Beta catalyst. The bifunctional Ni/H-Beta showed the BTX selectivity in liquid product and the total BTX yield as high as 69.5% and 40.7 wt%, respectively, at the tetralin conversion of 99.5% at 450 °C under 4 MPa. The catalytic behavior of Ni/H-Beta suggests that BTX yield can be much improved by properly controlling the hydrogenation power of metallic sites (i.e., suppressing the hydrogenation activity), the acidity of H-Beta and their balance on the bifunctional hydrocracking catalysts.
