- Experimental design optimization of the tetralin hydrogenation over Ir-Pt-SBA-15
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Experiment design-response surface methodology (RSM) is used in this work to model and optimize two responses in the hydrogenation of tetralin to decalin using bimetallic Ir-Pt-SBA-15 catalyst. In this study, we analyze the influence of the nature of the catalyst (metal molar fraction and metal loading), the catalyst/substrate ratio and the temperature of the reaction as factors for the design. The responses analyzed were conversion at 3 h and at 5 h of reaction time. The response surfaces were obtained with the Box-Behnken design, finding the best combination between the reaction parameters that allowed optimizing the process. By applying the statistic methodology, the higher levels of the two objective functions were obtained employing the catalyst with 1 wt.% of iridium and 0.7-0.8 wt.% of platinum; the optimal ratio between mass of catalyst and mole of tetralin was 17-19 g/mol and temperature between 200 and 220 °C.
- Valles, Vernica A.,Ledesma, Brenda C.,Rivoira, Lorena P.,Cussa, Jorgelina,Anunziata, Oscar A.,Beltramone, Andrea R.
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- Tuning of activity and selectivity of Ni/(Al)SBA-15 catalysts in naphthalene hydrogenation
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The hydrogenation of naphthalene was performed with nickel catalysts (4 wt. % of Ni) supported on SBA-15 and Al-SBA-15 in order to evaluate the effect of the support's acidity on the activity and selectivity of the catalysts. The incorporation of aluminum into the SBA-15 support was performed during the hydrothermal synthesis of the material with the aim to reach the isomorphic substitution of Si4+ by Al3+ leading to the generation of Br?nsted acid sites. Two different precursors (nickel nitrate and a Ni:EDTA complex) were used for the preparation of the catalysts on each support. Catalysts were characterized by nitrogen physisorption, powder X-ray diffraction, temperature programmed reduction, temperature programmed desorption of ammonia, scanning and high-resolution transmission electron microscopy. The Al-SBA-15 support was characterized by solid state 27Al MAS-NMR. The results showed that the intrinsic activity of the catalysts (TOF) increased when the Al-SBA-15 support and the Ni:EDTA complex were used in the catalyst's preparation. The catalysts prepared using the Ni:EDTA complex showed high selectivity to decalins and higher proportion of trans-decalin in the products than the catalysts prepared with nickel nitrate, which was attributed to a higher dispersion of the metallic Ni species and the larger total amount of acid sites.
- Vargas-Villagrán,Ramírez-Suárez,Ramírez-Mu?oz,Calzada,González-García,Klimova
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- Simultaneous Desulfurization and Hydrogenation of Model Diesel Fuel over Ni/ZnO–PdPt/USY Hybrid Catalyst
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Abstract: The clean production requires deep desulfurization to meet stringent environmental specification and aromatics hydrogenation to improve the quality of transport fuels. To achieve this objective, hybrid catalyst was prepared by mixing of PdPt/USY with Ni/ZnO powders. It was found that the hybrid showed higher activity and stability to hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation of tetralin than Ni/ZnO or PtPd/USY counterparts. PdPt/USY containing catalysts exhibited high trans/cis ration of decalin, this can be attributed to the isomerization on the acid sites of USY and the reduced interaction between olefinic intermediates with PdPt bimetals. The hybrid catalyst also had high hydrogenation ability and stability to bulky aromatics of pyrene with the existence of DBT. The XRD, XPS, and BET characterizations revealed that PdPt/USY is responsible for DBT HDS, HYD and isomerization whereas Ni/ZnO play supporting role as sulfur adsorbent in hybrid catalyst. Hydrogen spillover between Ni/ZnO and PdPt/USY components facilitates the aromatic hydrogenation and DBT HDS. This study proposed that the PdPt/USY–Ni/ZnO hybrid catalyst may be an alternative in the hydrotreatment of diesel fuel.
- Lichun Huang,Du, Mingxian,Wang, Weixing,Tang, Mingxing,Ge, Hui
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- Stereoselective hydrogenation of tetralin to cis-decalin over a carbon-supported rhodium catalyst in supercritical carbon dioxide solvent
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cis-Decalin was selectively obtained with high cis/trans ratio (83%) over a carbon-supported rhodium catalyst at 333 K under 6 MPa of hydrogen and 15 MPa of carbon dioxide. Copyright
- Hiyoshi, Norihito,Mine, Eiichi,Rode, Chandrashekhar V.,Sato, Osamu,Shirai, Masayuki
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- Simultaneous naphthalene and thiophene hydrogenation over Ni(X)-Pt/HMOR catalysts
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A series of Ni(X)-Pt/HMOR catalysts (X = 0, 0.5, 1.0, 1.5 and 2.0 wt% of Ni and a fixed quantity of Pt = 1 wt%) were prepared and tested in the hydrogenation (HYD) of naphthalene with and without thiophene and also in the hydroconversion of thiophene. The catalysts were characterized using N2 physisorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), transmission electron microscopy (TEM) and TEM-EDS elemental analysis. The TPR and TEM results indicate that Pt is mainly located inside the pore system of the mordenite, whereas Ni is located on both the external surface and inside the pore system of the mordenite zeolite. Naphthalene hydrogenation exhibited a high conversion for all the catalysts. In the presence of a sulfur compound and for naphthalene hydrogenation, all the tested catalysts present a fast deactivation. Ni/HMOR catalyst was less active and presents complete deactivation. However, the Ni(0.5)-Pt/HMOR and Pt/HMOR catalysts are able to convert thiophene and produce mainly tetrahydrothiophene. This hydrogenation activity was stable, at least for 12 h, showing that the catalytic system can preserve some of the hydrogenating capability. The values of thiophene hydroconversion and the selectivity to tetrahydrothiophene are much higher than the reported for similar systems. The hydrogenation activity is most likely due to the hydrogen spillover.
- Téllez-Romero,Cuevas-García,Ramírez,Castillo-Villalón,Contreras-Bárbara,Salcedo-Luna,Puente-Lee
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- Aromatic compound hydrogenation and hydrodeoxygenation method and application thereof
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The invention belongs to the technical field of medicines, and discloses an aromatic compound hydrogenation and hydrodeoxygenation method under mild conditions and application of the method in hydrogenation and hydrodeoxygenation reactions of the aromatic compounds and related mixtures. Specifically, the method comprises the following steps: contacting the aromatic compound or a mixture containing the aromatic compound with a catalyst and hydrogen with proper pressure in a solvent under a proper temperature condition, and reacting the hydrogen, the solvent and the aromatic compound under the action of the catalyst to obtain a corresponding hydrogenation product or/and a hydrodeoxygenation product without an oxygen-containing substituent group. The invention also discloses specific implementation conditions of the method and an aromatic compound structure type applicable to the method. The hydrogenation and hydrodeoxygenation reaction method used in the invention has the advantages of mild reaction conditions, high hydrodeoxygenation efficiency, wide substrate applicability, convenient post-treatment, and good laboratory and industrial application prospects.
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Paragraph 0094-0095; 0106-0113
(2021/05/29)
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- Discovery of a Neutral 40-PdII-Oxo Molecular Disk, [Pd40O24(OH)16{(CH3)2AsO2}16]: Synthesis, Structural Characterization, and Catalytic Studies
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We report on the synthesis and structural characterization of a giant, discrete, and neutral molecular disk, [Pd40O24(OH)16{(CH3)2AsO2}16] (Pd40), comprising a 40-palladium-oxo core that is capped by 16 dimethylarsinate moieties, resulting in a palladium-oxo cluster (POC) with a diameter of μ2 nm. Pd40, which is the largest known neutral Pd-based oxo cluster, can be isolated either as a discrete species or constituting a 3D H-bonded organic-inorganic framework (HOIF) with a 12-tungstate Keggin ion, [SiW12O40]4- or [GeW12O40]4-. 1H and 13C NMR as well as 1H-DOSY NMR studies indicate that Pd40 is stable in aqueous solution, which is also confirmed by ESI-MS studies. Pd40 was also immobilized on a mesoporous support (SBA15) followed by the generation of size-controlled Pd nanoparticles (diameter μ2-6 nm, as based on HR-TEM), leading to an effective heterogeneous hydrogenation catalyst for the transformation of various arenes to saturated carbocycles.
- Bhattacharya, Saurav,Bons, Anton-Jan,Cadot, Emmanuel,Espenship, Michael Forrester,Haouas, Mohamed,Jaensch, Helge,Kortz, Ulrich,Laskin, Julia,Ma, Xiang,Mougharbel, Ali S.,Stuerzer, Tobias,Su, Pei,Taffa, Dereje H.,Wark, Michael
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p. 17339 - 17347
(2021/11/17)
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- Uniformly sized Pt nanoparticles dispersed at high loading on Titania nanotubes
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A range of Pt loadings (0.9–21.5 wt. %) on titania nanotubes (TNT) catalysts were prepared with a view to address metal-support interaction effects on Pt nanoparticles (size, dispersion, shape) and were prepared by a vapor-phase impregnation method using Pt(acac). The reduced catalysts were characterized by XRD, TEM, H2-TPD, CO adsorption FTIR and examined as catalysts in naphthalene hydrogenation. Pt nanoparticles have a very uniform size between 1.4–2.2 nm for Pt loadings 0.9–21.5 wt% as indicated by TEM, H2-TPD and CO-adsorption FTIR. A strong metal-support interaction between Pt and TNT support hinder Pt nanoparticles to agglomerate into larger particles, even at high Pt loadings. Both Pt edge sites and exposed surface total Pt sites are highest at 10.2 wt.% Pt loading and parallels naphthalene hydrogenation activity which peaks at this loading.
- Chávez, C. Angeles,Cortés-Jácome, M. A.,Encarnación-Gómez, C.,García, J. R. Vargas,Hernández-Cortéz, J. G.,Hernández-Cruz, M. G.,López, I. Cuauhtémoc,Medina-Mendoza, A. K.,Salinas, E. López,Toledo-Antonio, J. A.
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- Facile in situ Encapsulation of Highly Dispersed Ni@MCM-41 for the Trans-Decalin Production from Hydrogenation of Naphthalene at Low Temperature
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Ni@MCM-41 catalyst that has uniformly distributed, highly dispersed Ni nanoparticles (about 2.3 nm) was designed and successfully synthesized by in situ encapsulation of Ni in the channels of MCM-41. This catalyst exhibits excellent thermal stability and hydrogenation activity. Water insoluble nickel acetylacetonate (Ni(acac)2) was first dissolved aqueous solution of cetyltrimethyl ammonium bromide (CTAB) and encapsulated in micelles of CTAB. Sodium silicate was used as a silicon source to rapidly hydrolyze and then wrap on the micelle surface to synthesize the MCM-41 zeolite. The MCM-41 zeolite encapsulating Ni(acac)2 was synthesized within a short time (4 h) at 120 °C. Compared with conventional supported catalysts, thus 3 wt.% Ni@MCM-41 has ultra-small uniformly distributed Ni nanoparticles and exhibits improved activity for the hydrogenation of naphthalene to decalin at very low reaction temperatures. The TOF and the apparent activation energy of Ni@MCM-41 and the conventional catalysts (Ni/MCM-41 and Pt/MCM-41) were evaluated and compared. And the catalysis mechanism was analyzed. Furthermore, this Ni@MCM-41 catalyst offers an additional advantage of selectivity in decalin isomerization; 92 % trans-decalin selectivity was achieved at a wide temperature range.
- Song, Xiaoyun,Guan, Qingxin,Shu, Yu,Zhang, Xiaojing,Li, Wei
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p. 1286 - 1294
(2019/01/25)
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- Synthesis of hierarchical zeolites by solid state crystallization of aluminosilicate nanogels
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Hierarchically porous ZSM-5 zeolites, having macropores, mesopores, and micropores are formed using a solid-state crystallization process. An aluminosilicate nanogel prepared with precursors, solvent, and a structure-directing agent is provided. The solvent is evaporated from the aluminosilicate nanogel at room temperature. The dried aluminosilicate nanogel is then heated to promote crystallization. The crystallized zeolites are calcined to remove the structure-directing agent.
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Page/Page column 9; 10; 15
(2019/07/19)
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- Properties of Nanosized Cobalt-Molybdenum Sulfide Catalyst Formed In Situ from Sulfonium Thiosalt
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Abstract: A cobalt-molybdenum-containing sulfonium thiosalt is prepared; when decomposed in situ, it forms the catalyst active in hydrogenation and hydrodesulfurization. The possibility of catalyst isolation and reuse in several hydrogenation cycles is shown. It is found that a lower selectivity for naphthalene hydrogenation products in catalyst recycling is associated with decrease in the dispersity of molybdenum sulfide nanoparticles and reduction in the degree of their promotion by cobalt atoms.
- Knyazeva,Panyukova,Maximov
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p. 504 - 510
(2019/06/19)
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- Stainless Steel-Mediated Hydrogen Generation from Alkanes and Diethyl Ether and Its Application for Arene Reduction
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Hydrogen gas can be generated from simple alkanes (e.g., n-pentane, n-hexane, etc.) and diethyl ether (Et2O) by mechanochemical energy using a planetary ball mill (SUS304, Fritsch Pulverisette 7), and the use of stainless steel balls and vessel is an important factor to generate the hydrogen. The reduction of organic compounds was also accomplished using the in-situ-generated hydrogen. While the use of pentane as the hydrogen source facilitated the reduction of the olefin moieties, the arene reduction could proceed using Et2O. Within the components (Fe, Cr, Ni, etc.) of the stainless steel, Cr was the metal factor for the hydrogen generation from the alkanes and Et2O, and Ni metal played the role of the hydrogenation catalyst.
- Sawama, Yoshinari,Yasukawa, Naoki,Ban, Kazuho,Goto, Ryota,Niikawa, Miki,Monguchi, Yasunari,Itoh, Miki,Sajiki, Hironao
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supporting information
p. 2892 - 2896
(2018/05/29)
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- Naphthalene Hydrogenation over Catalysts Formed In Situ from Ruthenium-Containing Thiosalts
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Abstract: Ruthenium-containing 1-butyl-1-methylpiperidinium thiosalts are synthesized; their decomposition in situ in a hydrocarbon medium makes it possible to form catalysts active in the hydrogenation of naphthalene. It is shown that the modification of thiosalts with nickel leads to the formation of more active catalyst systems. A thermally stable ionic liquid 1-butyl-1-methylpiperidinium trifluoromethanesulfonate is synthesized. It is shown that the hydrogenation catalyst may be prepared by the decomposition of thiosalts in the ionic liquid and that it can be reused in several cycles without any loss in activity.
- Onishchenko,Suzova,Maximov
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p. 1213 - 1220
(2019/02/05)
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- Polysilane-Immobilized Rh-Pt Bimetallic Nanoparticles as Powerful Arene Hydrogenation Catalysts: Synthesis, Reactions under Batch and Flow Conditions and Reaction Mechanism
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Hydrogenation of arenes is an important reaction not only for hydrogen storage and transport but also for the synthesis of functional molecules such as pharmaceuticals and biologically active compounds. Here, we describe the development of heterogeneous Rh-Pt bimetallic nanoparticle catalysts for the hydrogenation of arenes with inexpensive polysilane as support. The catalysts could be used in both batch and continuous-flow systems with high performance under mild conditions and showed wide substrate generality. In the continuous-flow system, the product could be obtained by simply passing the substrate and 1 atm H2 through a column packed with the catalyst. Remarkably, much higher catalytic performance was observed in the flow system than in the batch system, and extremely strong durability under continuous-flow conditions was demonstrated (>50 days continuous run; turnover number >3.4 × 105). Furthermore, details of the reaction mechanisms and the origin of different kinetics in batch and flow were studied, and the obtained knowledge was applied to develop completely selective arene hydrogenation of compounds containing two aromatic rings toward the synthesis of an active pharmaceutical ingredient.
- Miyamura, Hiroyuki,Suzuki, Aya,Yasukawa, Tomohiro,Kobayashi, Shu
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supporting information
p. 11325 - 11334
(2018/09/06)
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- The synthesis and mechanistic studies of a highly active nickel phosphide catalyst for naphthalene hydrodearomatization
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Although HDS and HDN reactions over transition metal phosphides have been widely studied, few publications about aromatic hydrodearomatization (HDA) over transition metal phosphides are found. Using ordered mesoporous Al-MCM-41 (Al-M) as the support, a series of supported nickel phosphide catalysts with different Ni/P molar ratios and loadings have been prepared by a temperature-programmed reduction and characterized. The HDA activity of naphthalene was measured in a fixed bed reactor at 250-330 °C and 3 MPa. The results showed that the catalyst with initial Ni/P molar ratio of 1.25 and 15 wt% loading displayed the highest HDA activity as well as 99.0% of selectivity of decalin at 270 °C, which is even higher than that of 0.5 wt% Pt-Al-M catalyst. As a comparison, the HDA performance of various catalysts was also examined. The results revealed that the presence of framework aluminum favors HDA processes and a synergistic effect between nickel phosphide and the suitable acidity resulted in an improvement of the catalytic activity. Finally, the possible reaction pathway of naphthalene hydrogenation (HYD) on nickel phosphide catalysts was proposed. Taking into consideration the high catalytic activity, Al-M supported nickel phosphide can be considered as a very efficient HDA catalyst to decrease the contents of aromatics in the fuels.
- Yun, Guoxia,Guan, Qingxin,Li, Wei
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p. 8677 - 8687
(2017/02/10)
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- Promotion of hydrogenation activity and sulfur resistance over Ni/ASA catalyst by support modification simultaneously with P and USY
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Individual and simultaneous P and USY promoted amorphous SiO2-Al2O3 (ASA) supported Ni catalysts were prepared using the hydrothermal synthesis method with the assistance of cis-9-octadecenylamine. The catalysts were characterized by X-ray diffraction (XRD), N2-adsorption and desorption, UV-vis diffuse reflectance spectroscopy, FTIR spectroscopy of adsorbed pyridine (Py-IR), transmission electron microscopy (TEM), temperature-programmed hydrogen reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The effects of P and USY loading on the activity of naphthalene hydrogenation were evaluated in a fixed bed reactor under the following reaction conditions: P = 4 MPa, GHSV = 16 h-1, H2/oil = 600 volume ratio, T = 200, 240, 280 and 320 °C. Experimental results verified that all individual P and USY modified catalysts displayed higher hydrogenation activity than the freely P and USY decorated catalyst at 200-280 °C. Furthermore, the catalyst simultaneously modified with 1.0 wt% P and 10 wt% USY had the highest hydrogenation activity and sulfur tolerance. Multiple effects, such as metal dispersion, acid amount, surface exposure of the active Ni° species and the [NiOh2+]/[NiTd2+] ratio were responsible for the high hydrogenation activity of P and USY-promoted catalysts.
- Cui, Sha,Ge, Jiaqi,Wang, Genggeng,Yang, Ying,Liu, Baijun
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p. 41460 - 41470
(2017/09/11)
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- Nickel–molybdenum sulfide naphthalene hydrogenation catalysts synthesized by the in situ decomposition of oil-soluble precursors
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Nickel–molybdenum sulfide catalysts for the hydrogenation of aromatic hydrocarbons have been prepared by the in situ decomposition of oil-soluble precursors Mo(CO)6 and Ni(С7H15СOO)2 in a hydrocarbon feedstock and characterized by HRTEM and XPS. The resulting Ni–Mo sulfide material exhibits high catalytic activity in the naphthalene hydrogenation reaction. An optimum Mo/Ni ratio of 1/2 has been selected.
- Sizova,Maksimov
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p. 595 - 599
(2017/07/22)
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- Nanoheterogeneous ruthenium-containing catalysts based on dendrimers in the hydrogenation of aromatic compounds under two-phase conditions
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Nanoheterogeneous catalysts based on ruthenium nanoparticles dispersed in crosslinked dendrimer matrixes with a size of polymer particles of 100–500 nm show high activity in the hydrogenation of aromatic compounds under two-phase conditions. The addition of water to the reaction medium exerts a strong promoting effect on the activity of the catalysts: The turnover frequency increases by a factor of 3–90 depending on the substrate. When bimetallic (PdRu) nanoparticles are incorporated into the catalyst composition, the rate of benzene hydrogenation increases while the rate of transformation of substituted benzenes decreases.
- Karakhanov,Maximov,Zolotukhina,Terenina,Vutolkina
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p. 491 - 502
(2016/07/29)
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- Synthesis of nickel-tungsten sulfide hydrodearomatization catalysts by the decomposition of oil-soluble precursors
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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.
- Sizova,Kulikov,Onishchenko,Serdyukov,Maksimov
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- Preparation of Ni - W aromatic hydrocarbon hydrogenation catalysts by breaking reverse emulsions or suspensions of a precursor in hydrocarbon feedstock
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Reverse emulsions (hydrocarbon feedstock)/(aqueous precursor solution) for synthesizing aromatic hydrocarbon hydrogenation catalysts have been prepared using the water-soluble salts (NH4)2WS4 and Ni(NO3)2·6 H2O as precursors. It has been found that the optimum stabilizer for the emulsions is the nonionic surfactant SPAN-80. The resulting emulsions exhibit low catalytic activity in the hydrogenation of aromatic hydrocarbons; it has been shown that the activity of the systems in hydrodearomatization reactions is adversely affected by the presence of water. A procedure for preparing suspensions of solid precursor particles in a hydrocarbon feedstock by the removal of water from the resulting reverse emulsions has been developed. The catalytic activity of the resulting suspensions in the hydrogenation of aromatic hydrocarbons has been studied using naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene as examples. It has been shown that the catalytic activity of the suspensions is higher than that of the reverse emulsions of the same composition. It has been found that the feedstock should be subjected to additional sulfurization with elemental sulfur for further sulfiding the surface of the nickel - tungsten catalyst. The W: Ni molar ratio of 1: 1 has been found to be optimum.
- Sizova,Serdyukov,Maksimov
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p. 131 - 137
(2016/04/20)
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- Synthesis of Ni–W aromatic hydrocarbon hydrogenation catalysts by the ex situ and in situ decomposition of a precursor based on a dendrimer network
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A Ni–W precursor supported on a dendrimer-containing crosslinked polymer (42 wt % of a third-generation polypropylenimine dendrimer) has been first synthesized. The precursor has been subjected to the ex situ and in situ decomposition in a hydrocarbon feedstock to prepare an unsupported Ni–W sulfide catalyst. The activity of the resulting catalyst in the hydrogenation of aromatic hydrocarbons has been studied using the example of naphthalene. The process has been conducted in an autoclave-type reactor in a temperature range of 350–400°C at a hydrogen pressure of 5.0 MPa. It has been shown that the in situ synthesis of a Ni–W catalyst leads to the formation of particles exhibiting higher activity in the hydrogenation of naphthalene. The in situ synthesized Ni–W particles have been characterized by TEM and XPS.
- Sizova,Kulikov,Zolotukhina,Serdyukov,Maksimov,Karakhanov
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p. 1107 - 1113
(2017/02/15)
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- METHODS FOR SELECTIVELY HYDROGENATING SUBSTITUTED ARENES WITH SUPPORTED ORGANOMETALLIC CATALYSTS
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Methods for selectively hydrogenating substituted arenes with a supported organometallic hydrogenating catalyst are provided. An exemplary method includes contacting a substituted arene-containing reaction stream with hydrogen in the presence of a supported organometallic hydrogenating catalyst under reaction conditions effective to selectively hydrogenate the substituted arenes to the cis isomer with high selectivity. In this method, the supported organometallic hydrogenating catalyst includes a catalytically active organometallic species and a Br?nsted acidic sulfated metal oxide support.
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Paragraph 0039
(2016/06/28)
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- Selective catalytic hydrogenation of polycyclic aromatic hydrocarbons promoted by ruthenium nanoparticles
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Ru nanoparticles stabilised by PPh3 are efficient catalysts for hydrogenation of polycyclic aromatic hydrocarbons (PAHs) containing 2-4 rings under mild reaction conditions. These compounds were partially hydrogenated with good to excellent selectivities just by optimizing the reaction conditions. The influence of the nature of substituents present in different positions of naphthalene on the selectivity of hydrogenation was also studied. Hydrogenation of products containing substituents at position 1 is slower than that of products containing substituents at position 2. In all cases, hydrogenation takes place mainly on the less substituted ring.
- Bresó-Femenia, Emma,Chaudret, Bruno,Castillón, Sergio
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p. 2741 - 2751
(2015/05/27)
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- Nickel-tungsten sulfide aromatic hydrocarbon hydrogenation catalysts synthesized in situ in a hydrocarbon medium
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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.
- Sizova,Serdyukov,Maksimov
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p. 470 - 480
(2015/11/23)
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- Hydrogen Self-Sufficient Arene Reduction to Cyclohexane Derivatives Using a Combination of Platinum on Carbon and 2-Propanol
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Various arenes have been hydrogenated using platinum on carbon in a 2-propanol-aqueous mixed solvent at 100 C without the addition of flammable hydrogen gas to give the corresponding cyclohexane derivatives. 2-Propanol plays a role as an efficient hydrogen source based on the platinum on carbon-catalyzed dehydrogenation.
- Sawama, Yoshinari,Mori, Misato,Yamada, Tsuyoshi,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 3667 - 3670
(2016/01/25)
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- Effect of ZrO2 in Ni2P/ZrO2-Al2O3 catalysts on hydrotreating reactions
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Catalysts 60% Ni/Al2O3 and 60% Ni/4% ZrO2-Al2O3 were prepared, and it was found that the addition of ZrO2 promoted reduction while maintaining the high dispersion of supported nickel. Upon phosphidation by triphenylphosphine (PPh3) in the liquid phase, the two catalysts were converted into corresponding Ni2P/Al2O3 and Ni2P/ZrO2-Al2O3 catalysts with highly dispersed Ni2P particles (6.3 and 6.8 nm, respectively), high CO uptakes (305 and 328 μmol g-1, respectively) and thus high activities for the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation of tetralin to decalin. In particular, the Ni2P/ZrO2-Al2O3 was found to be significantly more active than the Ni2P/Al2O3 for the HDS of DBT and hydrogenation of tetralin to decalin. Although the presence of ZrO2 did not affect the heat of adsorption of CO on Ni2P, it significantly increased the heat and uptake of adsorption of H2 on Ni2P, which might account for the increased activity of Ni2P promoted by ZrO2.
- Wang, Junen,Yuan, Yamei,Shuaib, Abdalla,Xu, Jun,Shen, Jianyi
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p. 74312 - 74319
(2015/09/21)
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- Deep hydrogenation of coal tar over a Ni/ZSM-5 catalyst
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We have developed a Ni/ZSM-5 catalyst and utilised it to completely hydrogenate a series of condensed arenes, including naphthalene, anthracene and phenanthrene, under relatively mild conditions. The yields of decalin, perhydroanthracene and perhydrophenanthrene reached 100%, 98.8% and 25.8%, respectively. By analyzing the isomer distribution of the perhydroarenes, we proposed a mechanism of biatomic hydrogen transfer, which was further proven via the hydrogenation of 9,10-diphenylanthracene. Through hydrotreatment over the Ni/ZSM-5 catalyst, both high-temperature coal tar rich in condensed arenes and low-temperature coal tar mixing arenes with alkanes were greatly upgraded. The majority of arenes in the coal tars were deeply and even completely hydrogenated, which may open up a route for further processing and application of coal tar as clean fuels.
- Qi, Shi-Chao,Zhang, Lu,Wei, Xian-Yong,Hayashi, Jun-Ichiro,Zong, Zhi-Min,Guo, Lu-Lu
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p. 17105 - 17109
(2014/05/06)
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- Chemical loop systems for biochar liquefaction: Hydrogenation of Naphthalene
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Liquefaction of biochar from liquid-phase pyrolysis was carried out in the solvent Tetralin. Tetralin is able to act as hydrogen donor during liquefaction of biochar and is itself rearranged into Naphthalene. Naphthalene must be re-hydrogenated to Tetralin to allow for further use in the liquefaction reaction (chemical loop system). Therefore Naphthalene hydrogenation was investigated, applying a full factorial design of experiments approach. The yield of Tetralin was chosen as response variable, while two-level-factors for temperature (150 °C and 200 °C), pressure (20 bar and 50 bar) and Raney-Nickel catalyst load (5 wt% and 10 wt%) were selected. The Design of Experiments approach showed a rising influence of all three factors in the order: temperature pressure catalyst load. The reaction kinetics of the hydrogenation of Naphthalene to Tetralin and Decalin was then investigated at 150 °C and 200 °C. The reaction proceeds stepwise and not in consecutive steps. In a first step Naphthalene reacts selectively with 96% yield to Tetralin, while the reaction of Tetralin to Decalin does not start until all Naphthalene is consumed. The rate-constant of the reaction of Naphthalene to Tetralin is one magnitude higher than that for the reaction of Naphthalene to Decalin. This is in agreement with the findings from the design of experiments approach. The results of these investigations indicate that the chemical-loop system Naphthalene-Tetralin is suitable for usage in the liquefaction of biochar.
- Feiner, Roland,Schwaiger, Nikolaus,Pucher, Hannes,Ellmaier, Lisa,Derntl, Michael,Pucher, Peter,Siebenhofer, Matthaeus
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p. 34955 - 34962
(2014/11/27)
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- Simple, chemoselective hydrogenation with thermodynamic stereocontrol
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Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad functional group compatibility and rapid reaction rates at standard temperature and pressure.
- Iwasaki, Kotaro,Wan, Kanny K.,Oppedisano, Alberto,Crossley, Steven W. M.,Shenvi, Ryan A.
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supporting information
p. 1300 - 1303
(2014/02/14)
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- Aliphatic C-H activation with aluminium trichloride-acetyl chloride: Expanding the scope of the Baddeley reaction for the functionalisation of saturated hydrocarbons
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The functionalisation of decalin by means of an "aliphatic Friedel-Crafts" reaction was reported over fifty years ago by Baddeley et al. This protocol is of current relevance in the context of C-H activation and here we demonstrate its applicability to a range of other saturated hydrocarbons. Structural elucidation of the products is described and a mechanistic rationale for their formation is presented. The "aliphatic Friedel-Crafts" procedure allows for production of novel oxygenated building blocks from abundant hydrocarbons and as such can be considered to add significant synthetic value in a single step.
- Lyall, Catherine L.,Uosis-Martin, Mario,Lowe, John P.,Mahon, Mary F.,Panto?, G. Dan,Lewis, Simon E.
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p. 1468 - 1475
(2013/05/21)
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- Unprecedented selectivity to the direct desulfurization (DDS) pathway in a highly active FeNi bimetallic phosphide catalyst
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The hydrodesulfurization (HDS) of the refractory compound 4,6-dimethyldibenzothiophene (DMDBT) normally proceeds through a hydrogenation pathway that removes the planarity of the ring system and makes the hindered sulfur atom more accessible to the desulfurization centers. In this study, a highly active dispersed bimetallic NiFeP catalyst is found to have high selectivity for a direct desulfurization pathway, which does not require prior hydrogenation. The compound has equal numbers of Ni and Fe atoms which extended X-ray absorption fine structure analysis indicates are distributed randomly in the hexagonal Fe2P structure, with just a slight enrichment of Fe on the surface. This is supported by density functional theory calculations. The remarkable properties of the catalyst are ascribed to a ligand effect of Fe on the active Ni atoms.
- Ted Oyama,Zhao, Haiyan,Freund, Hans-Joachim,Asakura, Kiyotaka,Wlodarczyk, Radoslaw,Sierka, Marek
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scheme or table
p. 1 - 5
(2012/03/10)
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- Kinetic modeling of pure hydrogen production from decalin
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We investigate the dehydrogenation of decalin for the production of pure hydrogen for fuel cell applications. Supported Pt catalysts can achieve about 98% conversion with > 99.9 % selectivity for the dehydrogenation reaction. Cracking reactions occur only at high temperature. The partially dehydrogenated product, tetralin, was formed with a molar selectivity 6 %, depending on the operating conditions. We investigated the kinetics of the dehydrogenation of decalin in a fixed-bed tubular reactor at 275-345 °C and atmospheric pressure. A Hougen-Watson-type kinetic model accounted for the dehydrogenation of cis- and trans-decalin as well as the isomerization between the two isomers, the formation of the intermediate tetralin and the final product, naphthalene. The rigorous discrimination between rival models led to parameter values that are statistically significant and satisfied the physicochemical criteria.
- Wang, Bo,Goodman, D. Wayne,Froment, Gilbert F.
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p. 229 - 238
(2008/09/17)
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- Good sulfur tolerance of a mesoporous Beta zeolite-supported palladium catalyst in the deep hydrogenation of aromatics
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The activities of a Pd catalyst supported on mesoporous Beta zeolite (Beta-H) were evaluated for the hydrogenation of naphthalene and pyrene in the absence and presence of 200-ppm sulfur and for the hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT). Compared with Pd/Al-MCM-41, the Pd/Beta-H catalyst exhibited better sulfur tolerance for hydrogenation of naphthalene and pyrene and higher activity for HDS of 4,6-DMDBT. The ratio of the hydrogenation of the second ring naphthalene in the absence and presence of 200-ppm sulfur for Pd/Beta-H was larger than that for Pd/Al-MCM-41 (0.47 vs 0.19). The desulfurization effect of Pd/Beta-H was greater than that of Pd/Al-MCM-41 (51 vs 35%). The difference in sulfur tolerance and HDS ability of the 2 catalysts is attributed to the difference in support acidity. Beta-H exhibited more acidic sites and a higher percentage of strong acidic sites than Al-MCM-41 (552 μmol/g and 43% vs 291 μmol/g and 18%).
- Tang, Tiandi,Yin, Chengyang,Wang, Lifeng,Ji, Yanyan,Xiao, Feng-Shou
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scheme or table
p. 125 - 133
(2009/02/08)
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- A surfactant-assisted preparation of well dispersed rhodium nanoparticles within the mesopores of AlSBA-15: Characterization and use in catalysis
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Well dispersed and efficient Rh(0) hydrogenation catalysts were obtained by the reduction of Rh(iii)-exchanged mesoporous aluminosilicates by sodium borohydride in the presence of N,N-dimethyl-N-cetyl-N-(2-hydroxyethyl) ammonium chloride. The Royal Society of Chemistry.
- Boutros, Maya,Denicourt-Nowicki, Audrey,Roucoux, Alain,Gengembre, Leon,Beaunier, Patricia,Gedeon, Antoine,Launay, Franck
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supporting information; body text
p. 2920 - 2922
(2009/02/03)
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- Rhodium nanoparticles entrapped in boehmite nanofibers: Recyclable catalyst for arene hydrogenation under mild conditions
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A new recyclable rhodium catalyst was synthesized by a simple procedure from readily available reagents, which showed high activities in the hydrogenation of various arenes under 1 atm H2 at room temperature. The Royal Society of Chemistry 2005.
- Park, In Soo,Kwon, Min Serk,Kim, Namdu,Lee, Jae Sung,Kang, Kyung Yeon,Park, Jaiwook
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p. 5667 - 5669
(2007/10/03)
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- A new type of nonsulfide hydrotreating catalyst: Nickel phosphide on carbon
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Nickel phosphide on carbon is successfully synthesized by temperature-programmed reduction as verified with X-ray diffraction and extended X-ray absorption fine structure measurements; it shows superior activity, selectivity, and stability for sulfur removal from the refractory compound 4,6-dimethyldibenzothiophene with a steady-state conversion of 99%, which is much higher than that of a commercial NiMoS/γ-Al2O3 catalyst of 68%. The Royal Society of Chemistry 2005.
- Shu, Yuying,Oyama, S. Ted
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p. 1143 - 1145
(2007/10/03)
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- Semivolatile and volatile compounds in combustion of polyethylene
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The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850°C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that α,ω-olefins, α-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors.
- Font, Rafael,Aracil, Ignacio,Fullana, Andrés,Conesa, Juan A.
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p. 615 - 627
(2007/10/03)
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- PREPARATION OF SELECTIVELY FLUORINATED ORGANIC COMPOUNDS
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The invention provides a method of selectively fluorinating an organic compound at an unactivated saturated sp hybridised carbon atom, the method comprising reacting the compound with a fluorinating agent containing an N-F bond. The carbon atom may be, for example, a tertiary carbon atom or a secondary carbon atom. The carbon atom may form part of a cyclic structure. The fluorinating agent may be any electrophilic fluorinating agent containing an N-F bond. Preferably, the fluorinating agent is an N-fluorinated diazoniabicycloalkane.
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- Isomerization of cycloheptane, cyclooctane, and cyclodecane catalyzed by sulfated zirconia - Comparison with open-chain alkanes
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The skeletal isomerization of cycloalkanes with the number of carbons greater than six, cycloheptane, cyclooctane, cyclodecane, and cyclododecane, was performed over sulfated zirconia in liquid phase at 50°C. A main product of methylcyclohexane was formed from cycloheptane via a protonated cyclopropane intermediate, protonated [4.1.0]bicycloheptane, together with small amounts of trans-1,2-dimethylcyclopentane, as- and trans-1,3- dimethylcyclopentanes, 1,1-dimethylcyclopentane, and ethylcyclopentane. A major product from cyclooctane was ethylcyclohexane via a protonated cyclobutane intermediate, protonated [4.2.0]bicyclooctane, followed by cis-1,3- dimethylcyclohexane in addition to small amounts of trans-1,2-, -1,3-, -1,4-dimethylcyclohexanes, 1,1-dimethylcyclohexane, and methylcycloheptane. The detailed reaction-paths for cycloheptane and cyclooctane were shown after additional examinations in reactions of methylcyclohexane, ethylcyclopentane, ethylcyclohexane, and 1,2-dimethylcyclohexane. Cyclodecane was dehydrogenated into cis- or trans-decaline with the evolution of a dihydrogen. Cyclododecane was converted into lots of products, more than 30 species.
- Satoh, Daishi,Matsuhashi, Hiromi,Nakamura, Hideo,Arata, Kazushi
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p. 4343 - 4349
(2007/10/03)
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- Single-step, highly active, and highly selective nanoparticle catalysts for the hydrogenation of key organic compounds
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Pores for cluster catalysts: Nanoparticles of both Ru5Pt and Ru10Pt2, uniformly distributed along the inner walls of mesoporous silica, exhibit high catalytic performance in the single-step hydrogenation of dimethyl terephthalate (DMT, to 1,4-cyclohexanedimethanol (CHDM); see scheme), of benzoic acid (to cyclohexane carboxylic acid), and of naphthalene (in the presence of sulfur) to cisdecalin.
- Raja, Robert,Khimyak, Tetyana,Thomas, John Meurig,Hermans, Sophie,Johnson, Brian F. G.
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p. 4638 - 4642
(2007/10/03)
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- Functional-Group-Directed Diastereoselective Hydrogenation of Aromatic Compounds
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Diastereoselective liquid phase hydrogenation of a series of monosubstituted indane and tetralin substrates was studied on supported rhodium catalysts. Predominantly the cis-cis diastereomer, obtained by hydrogenation from the diastereoface opposite the substituent (at the stereogenic center), and the cis-trans diastereomer, obtained by hydrogenation from the diastereoface on the same side as the substituent, were formed. The diastereoselectivity between the two isomers was dependent on the steric repulsion or the electronic attraction of the substituent with the surface of the catalyst. The hydroxyl group did not exhibit a strong attraction (haptophilicity), and the cis-cis diastereomer was obtained as the major product. The amino group exhibited a very high haptophilicity, yielding primarily the cis-trans diastereomer. The diastereoselectivity obtained in the hydrogenation of all the substrates was influenced on addition of bases to the reaction mixture. In the case of alcoholic substrates, the selectivity to the cis-trans diastereomer could be substantially increased with alkaline hydroxide additives.
- Ranade, Vidyadhar S.,Consiglio, Giambattista,Prins, Roel
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p. 8862 - 8867
(2007/10/03)
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- Preparation and characterisation of a highly active bimetallic (Pd-Ru) nanoparticle heterogeneous catalyst
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The mixed-metal carbonylate cluster [Pd6Ru6(CO)24]2- was used as a single-source precursor in the synthesis of a highly active hydrogenation catalyst (stoichiometry PdRu) which has been characterised by electron microscopy and X-ray absorption spectroscopy: PdRu readily hydrogenates alkenes and naphthalene (the latter predominantly to cis-decalin) under mild conditions.
- Raja, Robert,Sankar, Gopinathan,Hermans, Sophie,Shephard, Douglas S.,Bromley, Stefan,Thomas, John Meurig,Johnson, Brian F.G.
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p. 1571 - 1572
(2007/10/03)
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- Hydrogenation of Aromatics in Diesel Fuels on Pt/MCM-41 Catalysts
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The hydrogenation activity of Pt supported on two mesoporous MCM-41 samples differing in their chemical composition has been studied by following the kinetics of the hydrogenation of naphthalene at 225-275°C reaction temperature and 5.0 MPa total pressure and by comparing the kinetic parameters obtained with Pt supported on a mesoporous amorphous silica-alumina (MSA) and other conventional supports, such as commercial amorphous silica-alumina (ASA), zeolite USY, γ-alumina, and silica. The two mesoporous MCM-41 and MSA materials having very high surface areas allowed for a better dispersion of the Pt particles, and they showed a superior overall hydrogenation activity as compared to the other supports. However, Pt/USY displayed the highest turnover (activity per exposed surface Pt), owing to the interaction of small Pt aggregates in the supercage of the zeolite with the strong Broensted acid sites associated to framework aluminum forming electron-deficient Pt species of known enhanced activity. Moreover, both the Al-MCM-41 and USY-based catalysts presented the highest sulfur tolerance during the hydrogenation of a naphthalene feed containing 200 ppm sulfur added as dibenzothiophene. The high metal dispersion and the interaction of the small Pt clusters with the mildly acidic sites present in Al-MCM-41 may account for its high sulfur tolerance. The superior hydrogenation activity and sulfur tolerance of Pt-MCM-41 catalyst observed in the naphthalene experiments were further confirmed during the hydrogenation of a hydrotreated light cycle oil (LCO) feed containing ca 70 wt% aromatics and 400 ppm sulfur.
- Corma,Martinez,Martinez-Soria
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p. 480 - 489
(2007/10/03)
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- Singlet and Triplet Excited-state Formation in High-energy Electron Tracks in Liquid cis- and trans-Decalin as studied by Product Formation in Radiolysis and Photolysis
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The yields of products formed as a result of irradiation of liquid cis- and trans-decalin with γ-rays and 3 MeV electrons as well as with 7.6 eV photons have been determined by means of gas-liquid chromatography (GLC).The major products for both cis- and trans-decalin are hydrogen, unsaturated C10 products and dimers; in the case of cis-decalin, cis-trans isomerization takes place via a chain reaction.Singlet and triplet excited states are formed by direct excitation and by charge recombination in the tracks of high-energy electrons.The product formation resulting from the singlets is determined by the photolysis.From a knowledge of the total yield of singlets from the radiolysis, the contribution of the singlet excited states to product formation during radiolysis is calculated and the remaining products are assigned to the triplets.For the sum of the yields of singlets and triplets a value of 6.4 (100 eV)-1 (=6.6E-7 mol J-1) is found for cis-decalin and 6.0 (100 eV)-1 (=6.2E-7 mol J-1) for trans-decalin and for the singlet fractions 0.53 and 0.47 in cis- and trans-decalin, respectively.The probability of C-H bond breakage in the singlet and triplet states is 0.42 and 0.82, respectively, for cis-decalin and 0.50 and 0.94, respectively, for trans-decalin.
- Hummel, A.,Leng, H. C. de,Luthjens, L. H.,Wojnarovits, L.
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p. 2459 - 2466
(2007/10/02)
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- Chemoselectivity in Catalytic Transfer Hydrogenation - Reduction of Alkenes and Alkynes with the H2PO2-NH4+*H2O/Pd-C System
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The H2PO2-*H2O/Pd-C system acts as an unusually powerful reducing agent, which is able to reduce cyclooctene to cyclooctane, Δ9,10-octalin to decalins, α- and β-pinenes to pinanes at room temperature in high yield without the formation of byproducts.This system reduces each of these compounds or partly (alkynes to alkenes), depending on the competition between the transfer hydrogenation to give alkanes and the protonolysis to give hydrogen gas on the palladium catalyst. - Key Words: Chemoselectivity/ Protonolysis/ Transfer hydrogenation/ Alkenes, reduction of/ Alkynes, reduction of
- Khai, Bui The,Arcelli, Antionio
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p. 2265 - 2268
(2007/10/02)
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- Hydrogenation of Aromatic Hydrocarbons by Al/Ti Reagents
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Treatment of anthracene (A) with LiAlH4 (LAH) at 150 deg C under atmospheric pressure gives 9,10-di- and 1,2,3,4-tetrahydroanthracene (2H-A and 4H-A).At 160-200 deg C and under hydrogen pressure (10-90 bar) a number of simple and polycyclic aromatic compounds are converted to fully or partially hydrogenated arenes.Addition of small amounts of TiCl4 or TiCl3 and the choice of solvents (heptane or glymes) have marked effects on the reaction.The pair triethylaluminium/TiCl4 acts also as efficient hydrogenation catalyst.
- Yalpani, Mohamed
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p. 983 - 987
(2007/10/02)
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- KINETICS FOR SIMULTANEOUS HDS, HDN AND HYDROGENATION MODEL REACTIONS ON A Co-Mo/Al2O3 CATALYST
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A kinetic analysis of simultaneous hydrodesulfurization (HDS) of dibenzothiophene (DBT), hydrodenitrogenation (HDN) of indole (IN) and hydrogenation (HYD) of naphthalene (NAP) is carried out.These compounds represent the major functional groups in heavy petroleum feeds.The goal of these experiments is to simulate the performance of a commercial catalyst with more complex feedstocks.The purposes are to determine the competitive inhibition effects of the various reactants as well as to investigate a microscopic model which can be generalized to more realistic feedstocks.Kinetic data are generated over a CoMo/Al2O3 catalyst in a temperature range of 260-350 deg C and total pressure of 25-81 105 Pa.The partial pressures of hydrogen and the other reactants are varied individually.From the data, a kinetic model is developed based on the competitive chemisorption of reactants, intermediates and products on identical surface sites.The kinetic model developed accounts for rates of appearance of the products and rates of disappearance of DBT, NAP and IN.The results suggest that compounds containing sulfur, nitrogen, aromatics or aliphatics are adsorbed with very different strength.
- Zeuthen, Per,Stolze, Per,Pedersen, Ulla B.
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p. 985 - 996
(2007/10/02)
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- Mechanism of Hydrogenolysis. Part 1. Catalytic Hydrogenation of Vinyl and Aryltrifluoromethanesulphonates
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A concerted cleavage of the C-O bond by the MH2 species is proposed for the first step of the catalytic hydrogenation of vinyl and aryl trifluoromethanesulphonates.The alkene thus generated in the case of vinyl trifluoromethanesulphonates, is subsequently, reduced to an alkane.The stereochemistry of the reduction of vinyl trifluoromethanesulphonates is therefore identical to that observed in the reduction of the corresponding alkenes.
- Martinez, Antonio Garcia,Alvarez, Roberto Martinez,Aguirre, Juan Arranz,Subramanian, R. L.
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p. 1595 - 1598
(2007/10/02)
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