92-51-3Relevant articles and documents
Hydrogenation of biphenyl and isomeric terphenyls over a Pt-containing catalyst
Kalenchuk,Koklin,Bogdan,Kustov
, p. 1208 - 1212 (2017)
Catalytic hydrogenation of benzene, biphenyl, and ortho-, metha-, and para-isomers of terphenyl over a 3 wt.% Pt/C at 180 °C and 70 atm was studied. The directions of hydrogenation of each substrate were revealed. Relationships between structures of the substrate and hydrogen consumption rates were found. It was shown that hydrogenation rate decreases on going from benzene to terphenyl and with increasing degree of the substrate hydrogenation. Hydrogenation rate of terphenyl isomers decreases in the following order: p-terphenyl > > m-terphenyl > o-terphenyl.
Thermal isomerizations of cis,anti,cis-tricyclo[6.4.0.02,7]dodec-3-ene?to trans- and cis,endo-tricyclo[6.2.2.02,7]dodec-9-ene: diradical conformations and stereochemical outcomes in [1,3] carbon shifts
Leber, Phyllis A.,Bogdan, Andrew R.,Powers, David C.,Baldwin, John E.
, p. 6331 - 6338 (2007)
The gas-phase thermal isomerizations at 315 °C of cis,anti,cis-tricyclo[6.4.0.02,7]dodec-3-ene to trans-tricyclo[6.2.2.02,7]dodec-9-ene and to cis,endo-tricyclo[6.2.2.02,7]dodec-9-ene favor the former, the more geometrically strained product, by a ratio of 2.4:1. These products correspond to suprafacial inversion (si) and suprafacial retention (sr) stereochemical outcomes. The reaction stereochemistry shown by the 11-carbon homolog, cis,anti,cis-tricyclo[6.3.0.02,7]undec-3-ene, is strikingly different: the [1,3] carbon shift takes place to give only the 'forbidden' sr product. Two related bicyclic vinylcyclobutanes, 8-deuterio- and 8-exo-methylbicyclo[4.2.0]oct-2-enes, evidence contrasting reaction stereochemical predilections in [1,3] shifts, but the 12-carbon tricyclic system and the 8-exo-methyl bicyclic analog isomerize with the same si:sr ratio! These observations prompt fresh considerations of structural influences on conformational preferences available to the alkyl, allyl diradical reactive intermediates involved.
ArF Excimer Laser-induced Selective Coupling of Cycloalkanes: Photochemical Reaction at the Absorption Edge
Ouchi, Akihiko,Yabe, Akira,Inoue, Yoshihisa,Daino, Yoshihiko,Hakushi, Tadao
, p. 1669 - 1671 (1989)
Bicycloalkyls were selectively produced from the corresponding liquid phase cycloalkanes by irradiation at their absorption edge with ArF excimer laser; the photoreaction proceeded by a radical mechanism and showed a dependence of the dimerization rate on ring size.
Supported Pt-Ni bimetallic nanoparticles catalyzed hydrodeoxygenation of dibenzofuran with high selectivity to bicyclohexane
Wu, Pengyu,Cai, Chun
supporting information, p. 234 - 238 (2021/07/10)
Catalytic hydrodeoxygenation (HDO) is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons. Herein, an efficient bimetallic catalyst Pt1Ni4/MgO was prepared and applied in the HDO of dibenzofuran (DBF). High yield (95%) of the desired product bicyclohexane (BCH) was achieved at 240 °C and 1.2 MPa of H2. Superior catalytic performance could be ascribed to the “relay catalysis” of Pt sites and Ni sites, and the reaction pathway is proposed as well. Scale-up experiment and recyclability test were also performed, which demonstrated the recyclability and promising potential application of Pt1Ni4/MgO.
Bulk hydrotreating MonW12-nS2 catalysts based on SiMonW12-n heteropolyacids prepared by alumina elimination method
Kokliukhin,Nikulshina,Mozhaev,Lancelot,Lamonier,Nuns,Blanchard,Bugaev,Nikulshin
, p. 26 - 37 (2020/08/21)
A series of unsupported mono- and bimetallic MonW12-nS2 catalysts were synthesized by alumina elimination from supported MonW12-nS2/Al2O3 samples using acid etching. Alumina supported catalysts have been in turn prepared by using monometallic H4SiMo12O40 and H4SiW12O40 heteropolyacids (HPAs), their mixture with Mo/W atomic ratio equal to 1/11 and 3/9, and mixed bimetallic H4SiMo1W11O40 and H4SiMo3W9O40 HPAs. All catalysts were characterized by N2 adsorption, temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), time-of-flight secondary ion mass spectrometry (ToF-SIMS), extended X-ray absorption fine structure (EXAFS) spectroscopy and powder X-ray diffraction (XRD) and their performance were evaluated in simultaneous hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation (HYD) of naphthalene. The etching process led to a successful removal of all the support and of the partially sulfided species, with sulfidation degrees of both Mo and W above 90 % on the final bulk solids. The active phase also underwent a rearrangement, as higher average length and stacking were measured on the bulk catalysts than on the original supported ones. Mixed MoWS2 phase was evidenced in all solids, prepared from mixed HPAs (MonW12-nS2) or from the mixture of monometallic HPAs (RefMonW12-nS2), by EXAFS and ToF-SIMS, with however a larger quantity on the MoW solids. It seems that the mixed MoWS2 phase observed on the supported MoW catalysts is maintained through the etching process, while on RefMonW12-nS2 the mixed phase, observed in a much lesser extent in the corresponding supported catalyst, could result from the aggregation of the monometallic slabs. MonW12-nS2 catalysts were found more effective than the monometallic catalysts and than the corresponding RefMonW12-nS2, in both dibenzothiophene hydrodesulfurization and naphthalene hydrogenation, which was related to the presence of the mixed phase maintained through the etching of the support.
The use of inorganic Al-HMS as a support for NiMoW sulfide HDS catalysts
Alonso-Nú?ez, G.,Huirache-Acu?a, R.,Maya-Yescas, R.,Pawelec, B.,Rivera-Mu?oz, E. M.,Vázquez, P. J.,Zepeda, T. A.
, (2021/05/27)
Inorganic hexagonal mesoporous silica (HMS) and aluminum modified HMS materials (Al-HMS) were prepared and used as supports of transition metal sulfide hydrodesulfurization (HDS) catalysts based on nickel, molybdenum, and tungsten as active phase. The samples were characterized with XRD, HRTEM, TPD, N2 physisorption and UV–Vis. The catalytic activity of the trimetallic catalysts was performed in the HDS of dibenzothiophene (DBT). When Al was incorporated into the inorganic support, important changes and effects were observed on the physicochemical properties. On the other hand, the incorporation of Al into the HMS led to a decrease in the reaction rate (k) and a trend toward a direct path of desulfurization was observed for all materials.
HYDRODESULFURIZATION CATALYST WITH A ZEOLITE-GRAPHENE MATERIAL COMPOSITE SUPPORT AND METHODS THEREOF
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Paragraph 0152; 0162, (2021/01/29)
A hydrodesulfurization catalyst, which includes (i) a catalyst support including a zeolite doped with 0.1 to 0.5 wt. % of a graphene material, based on a total weight of the catalyst support, (ii) 5 to 20 wt. % of molybdenum, based on a total weight of the hydrodesulfurization catalyst, and (iii) 1 to 6 wt. % of a promoter selected from the group consisting of cobalt and nickel, based on a total weight of the hydrodesulfurization catalyst. The molybdenum and the promoter are homogeneously disposed on the catalyst support. A method of producing the hydrodesulfurization catalyst via incipient wetness impregnation techniques, and a method for desulfurizing a hydrocarbon feedstock with the hydrodesulfurization catalyst are also provided.
Aromatic compound hydrogenation and hydrodeoxygenation method and application thereof
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Paragraph 0094-0097; 0100-0104, (2021/05/29)
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.
Selective hydrogenation of lignin-derived compounds under mild conditions
Chen, Lu,Van Muyden, Antoine P.,Cui, Xinjiang,Laurenczy, Gabor,Dyson, Paul J.
supporting information, p. 3069 - 3073 (2020/06/17)
A key challenge in the production of lignin-derived chemicals is to reduce the energy intensive processes used in their production. Here, we show that well-defined Rh nanoparticles dispersed in sub-micrometer size carbon hollow spheres, are able to hydrogenate lignin derived products under mild conditions (30 °C, 5 bar H2), in water. The optimum catalyst exhibits excellent selectivity and activity in the conversion of phenol to cyclohexanol and other related substrates including aryl ethers.
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.
