107-83-5Relevant articles and documents
EFFECT OF HYDROGEN PARTIAL PRESSURE ON CATALYTIC TRANSFORMATIONS OF C6 ALKANES AND METHYLCYCLOPENTANE ON Pt/C
Olfer'eva, T. G.,Krasavin, S. A.,Bragin, O. V.
, p. 447 - 452 (1981)
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Comparative studies on enzyme activity of immobilized horseradish peroxidase in silica nanomaterials with three different shapes and methoxychlor degradation of vesicle-like mesoporous SiO2 as carrier
Yang, Yuxiang,Zhao, Min,Yao, Pingping,Huang, Yan,Dai, Zuocheng,Yuan, Hongming,Ni, Chaoying
, p. 2971 - 2978 (2018)
In the present work, three differently shaped mesoporous silica nanoparticles, spherical nano-SiO2, tubular mesoporous SiO2 and vesicle-like mesoporous SiO2 (VSL), were prepared and used to immobilize Horse radish peroxida
Morschner,Cormody
, p. 604,606 (1951)
Ionic Hydrogenations using Transition Metal Hydrides. Rapid Hydrogenation of Hindered Alkenes at Low Temperature
Bullock, R. Morris,Rappoli, Brian J.
, p. 1447 - 1448 (1989)
Tetra-substituted, tri-substituted, and 1,1-disubstituted alkenes can be rapidly hydrogenated in high yield at -75 deg C using CF3SO3H/HMo(CO)3(C5H5) or CF3SO3H/HSiEt3
ETUDE DE L'ISOMERISATION DU METHYL-4 PENTENE-1 PAR L'HYDRIDO DIAZOTE TRIS(TRIPHENYLPHOSPHINE)COBALT(I): CoHN2(PPh3)3
Petit, F.,Arzouyan, C.,Peiffer, G.,Gaydou, E.
, p. 261 - 272 (1981)
At 25 deg C, and under 1 to 7 bar nitrogen pressure, the isomerization of 4-methyl-1-pentene catalyzed in benzene by CoHN2(PPh3)3 involves two active species: HCoN2(S1)(PPh3)2 and HCo(S1)(PPh3)3, respectively, in greater quantities at higher (P(N2) > 7 bars) and small quantities at P(N2) - O nitrogen pressures. The kinetic study shows that the rate of the reaction is always ruled by the equation:
Hindin et al.
, p. 538,540 (1955)
Transformations of n-Hexane over EUROPT-1: Fragments and C6 Products on Fresh and Partially Deactivated Catalyst
Paal, Zoltan,Groeneweg, Helga,Paal-Lukacs, Julia
, p. 3159 - 3166 (1990)
The reactions of n-hexane have been studied on 6.3percent Pt/SiO2 (EUROPT-1) at different hydrogen and n-hexane pressures, and at 543-633 K, over fresh catalyst and over catalysts deactivated by long runs.Turnover numbers are compared with literature data: the differences are attributed to hydrogen pressure effects.Deactivation influences first of all, selectivity.In addition, the 'depth' and 'pattern' of hydrogenolysis have been determined.At low temperature multiple splitting seems to be favoured.Isomerization gives predominantly 3-methylpentane.At medium temperatures, isomerization, C5-cyclization and internal splitting prevall; their ratio is controlled by the hydrogen pressure.The ratio of 2-methylpentane to 3-methylpentane is related to the ratio of internal to terminal rupture.Terminal splitting prevails at highest temperature.Aromatization increases with temperature but seems to be independent of the other reactions.The results are interpreted in terms of three different surface states.These correspond to Pt-H, Pt-C-H and Pt-C under increasing severity of conditions.
Cyclohexane transformations over metal oxide catalysts 2. Selective cyclohexane ring opening to form n-hexane over mono- and bimetallic rhodium catalysts
Vasina, T. V.,Masloboishchikova, O. V.,Khelkovskaya-Sergeeva, E. G.,Kustov, L. M.,Zeuthen, P.
, (2002)
The activity of monometallic Rh and Pt catalysts and bimetallic Pt-Rh catalysts on oxide supports in cyclohexane ring opening to form n-hexane was studied. The Rh-containing catalysts are highly active and selective in this reaction. Cyclohexane dehydroge
ACID CATALYSIS BY DEALUMINATED ZEOLITE Y. 2. THE ROLES OF ALUMINUM
Sohn, Jong Rack,DeCanio, Stephen J.,Fritz, Paul O.,Lunsford, Jack H.
, p. 4847 - 4851 (1986)
Hexane cracking activity was determined for a series of dealuminated zeolites which were prepared both by treatment with SiCl4 and by reaction with steam.Over a range of Si/Al ratios from 4.7 to 255 the cracking activity increased in a linear manner with respect to the number of lattice Al ions per unit cell.Thus, a constant turnover frequency is obtained, which is taken as evidence that the acid strenght does not vary over this range of Si/Al ratios.By contrast, a zeolite prepared by deamination of NH4-Y was very much less active than expected on the basis of the number of protonic sites.The acidity of the protons in this material is clearly less than in the dealuminated zeolite.These results support a model of strong Broensted acidity in which a structural aluminum atom has no next-nearest aluminum neighbors in a common 4-ring of the zeolite.
Investigation of active metal species formation in Pd-promoted sulfated zirconia isomerization catalyst
Belskaya, Olga B.,Danilova, Irina G.,Kazakov, Maxim O.,Gulyaeva, Tatyana I.,Kibis, Lidiya S.,Boronin, Andrey I.,Lavrenov, Alexander V.,Likholobov, Vladimir A.
, p. 5 - 12 (2010)
The state of palladium in Pd/SO42--ZrO2 (Pd/SZ) isomerization catalyst was investigated by the temperature-programmed reduction (TPR), chemisorption technique, infrared spectroscopy of adsorbed carbon monoxide (FTIRS), X-ray photoelectron spectroscopy (XPS), diffuse-reflectance UV-vis spectroscopy (UV-vis DRS), and benzene hydrogenation as a test reaction. It has been stated that reduction temperature has a great impact on the metal function of Pd-promoted sulfated zirconia catalyst. Metal centers are formed at about 30-70 °C and characterized by high palladium dispersion and activity in benzene hydrogenation. At temperatures above 200 °C, intensive sulfate decomposition occurs and products of sulfate reduction poison the metal function of the catalyst. According to XPS and FTIRS study, palladium particles in the poisoned samples are only partly oxidized, but the main part is presented by metallic phase without large amount of PdS. Reduction of Pd-containing catalyst at 150 °C (instead of 250 °C) leads to higher conversion and 2,2-dimethylbutane yield in acid-catalyzed reaction of n-hexane isomerization. Higher isomerization activity in this case is provided by prevention of active sulfate species decomposition due to the capability of palladium metallic particles formation at low reduction temperatures.
Levitskii et al.
, (1971)
Freidlin et al.
, (1956)
Hydrogenation of methyl isobutyl ketone over bifunctional Pt-zeolite catalyst
Alotaibi, Mshari A.,Kozhevnikova, Elena F.,Kozhevnikov, Ivan V.
, p. 141 - 144 (2012)
Methyl isobutyl ketone (MIBK) can be viewed as a key intermediate for the conversion of biomass-derived acetone - the by-product of biobutanol production - to transportation fuel. Zeolite H-ZSM-5 doped with Pt nanoparticles was found to be a highly efficient catalyst for gas-phase hydrogenation of MIBK to methylpentanes with >99% yield at 200 °C. The reaction proceeds via bifunctional metal-acid catalysed pathway involving MIBK hydrogenation to 4-methyl-2-pentanol (MP-ol) on metal sites followed by MP-ol dehydration on acid sites to form olefin and finally olefin hydrogenation to 2-methylpentane (2MP) on metal sites, with all three steps occurring on a single catalyst bed. 2MP thus obtained underwent isomerisation over bifunctional Pt/H-ZSM-5 catalyst to give a mixture of 2- and 3-methylpentanes in a ratio of 83:17. The catalyst did not show any deactivation for at least 16 h on stream.
Iridium Clusters in KLTL Zeolite: Structure and Catalytic Selectivity for n-Hexane Aromatization
Triantafillou, N. D.,Miller, J. T.,Gates, B. C.
, p. 131 - 140 (1995)
Catalysts consisting of Ir clusters in zeolite KLTL were prepared by reduction of Cl2 in the zeolite with H2 at temperatures 300 or 500 deg C.The catalysts were tested for reactions of n-hexane and H2 at 400, 440, and 480 deg C and were characterized by temperature-programmed reduction, hydrogen chemisorption, transmission electron microscopy, infrared spectroscopy of adsorbed CO, and extended X-ray absorption fine structure spectroscopy.The cluster consist of 4 to 6 IR atoms on average and are sufficiently small to reside within the pores of the zeolite.The infrared spectra characteristic of terminal CO suggest that the support environment is slightly basic and that the Ir clusters are electron rich relative to the bulk metal.Notwithstanding the small cluster size, the support basicity, and the confining geometry of the LTL zeolite pore structure, the catalytic performance is similar to those of other Ir catalysts, with a poor selectivity for aromatization and a high selectivity for hydrogenolysis.These results are consistent with the inference that the principal requirements for selective naphtha aromatization catalysts are both a nonacidic support and a metal with a low hydrogenolysis activity, i.e., Pt.
REACTION CHROMATOGRAPHY - MASS SPECTROMETRY 1. GAS CHROMATOGRAPH - HYDROGENATION MICROREACTOR - MASS SPECTROMETER SYSTEM FOR THE STUDY OF OLEFINNS
Mikaya, A. I.,Smetanin, V. I.,Zaikin, V. G.
, p. 1999 - 2005 (1982)
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The Influence of Reaction Temperature on the Cracking Mechanism of 2-Methylhexane
Bamwenda, G. R.,Zhao, Y. X.,Wojciechowski, B. W.
, p. 595 - 606 (1994)
The cracking of 2-methylhexane on USHY has been studied in the temperature range 400-500 deg C.It was found that this reaction leads to the formation of hydrogen, paraffins, olefins, and aromatics ranging from C1 to C10.Of these only hydrogen, C1-C7 compounds, and coke were found to be primary products.Mechanistic considerations indicate that two main processses take place during 2-methylhexane conversion on USHY: (1) initiation by protolysis on pristine Broensted sites; (2) chain processes involving isomerization, hydrogen transfer, and disproportionation.At low temperatures, cpnversion of 2-methylhexane proceeds to a significant extent via both mechanisms, while at higher temperatures protolytic cracking is the dominant process by far.We find that protolysis accounts for 67, 83, and 94percent of total conversion of 2-methylhexane at 400, 450, and 500 deg C, respectively.The average activation energy for protolytic cracking of 2-methylhexane on USHY was found to be 159 kJ/mol.The unexpectedly low activation energy for protolysis vis-a-vis the comparable value in 2-methylpentane cracking (246 kJ/mol) is discussed in terms of temperature effects on active densities and in terms of the compensation effect in protolysis.Hydride abstraction from gas phase 2-methylhexane by C6H13+ and C7H15+ ions leads to the formation of the paraffinic C6 and C7 skeletal isomers found in the primary products.In addition to hydride transfer, the set of active bimolecular chain reactions involves some but not all possible disproportionations between feed molecules and carbenium ions in the range C2H5+ and C5H1111.The reasons for this specifificity in disproportionation are discussed.The probability of initial coke formation was found to decrease with increasing temperature, suggesting a diminished rate of bimolecular reaction between adjacent carbenium ions at higher temperatures.We explain this as being the result of lower surface coverage by carbenium ions at elevated temperatures.
CATALYTIC PROPERTIES OF SUPERHIGH-SILICA ZEOLITES IN CONVERSIONS OF CERTAIN HYDROCARBONS
Minachev, Kh. M.,Garanin, V. I.,Isakova, T. A.,Mironova, I. L.,Fomin, A. S.,Lipkind, B. A.
, (1982)
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Catalysis with Palladium Deposited on Rare Earth Oxides: Influence of the Support on Reforming and Syngas Activity and Selectivity
Normand, F. Le,Barrault, J.,Breault, R.,Hilaire, L.,Kiennemann, A.
, p. 257 - 269 (1991)
The influence of the support has been tested on the reactivity of Pd/rare earth oxides catalysts (La2O3, CeO2, Pr6O11, Nd2O3, Tb4O7).According to BET surface area, chemisorption, temperature-programmed reduction (TPR) and oxidation (TPO), X-ray diffraction (XRD) and X-ray photoemission (XPS) characterizations, these catalysts have been classified into threeclasses according to their ability to create anion vacancies: (i) oxides of the type Re2O3 which are unreducible, (ii) CeO2 where anion vacancies can be created extrinsically by the reduction process, and (iii) Pr6O11 and Tb4O7 where anion vacancies exist due to the nonstoichiometric nature of these oxides.We emphasize also the role of chlorine, coming from the palladium precursor salt, which reacts with the support to form a stable oxychloride phase surrounding the metallic particle and interacting with it.Concerning the catalytic activity, (i) the active site is purely metallic in methylcyclopentane hydrogenolysis, with small selectivity changes on fluorite oxides as compared to Pd/Al2O3 catalysts due to some electronic interaction with the support, but (ii) the mechanism is found to be partly bifunctional in 3-methylhexane aromatization with a large increase in aromatization on Pr6O11 and Tb4O7 supports, and (iii) in syngas conversion, production of high alcohols occurs at the metal-support interface and is favored by the presence of intrinsic anion vacancies on Pr6O11 and Tb4O7 supports.A correlation is found between the density of anion vacancies on these supports and the chain growth probability deduced from the Anderson-Schulz-Flory plot.
Schneider
, p. 2553,2554 (1952)
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Cramer,Mulligan
, p. 374 (1936)
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Turner et al.
, p. 4315 (1968)
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Krishnamurthy,Brown
, p. 3064 (1976)
Weisang,Gault
, p. 519,520 (1979)
Ring opening of methylcyclopentane on alumina-supported Rh catalysts of different metal loadings
Teschner,Matusek,Paal
, p. 335 - 343 (2000)
The hydrogenolytic ring opening of methylcyclopentane (MCP) was studied on Rh/Al2O3 catalysts (prepared by the incipient wetness process) with varied metal loadings (0.3, 3, and 10%) and altered reduction temperatures, i.e., low-temperature range (573 K, LTR) and high-temperature range (973 K, HTR). The catalysts exhibited a ″selective″ ring-opening mechanism for MCP. Strong dependence was observed in the distribution of ring-opening products as a function of hydrogen pressure and temperature with 10Rh and 3RhHTR. However, 0.3Rh, 3RhLTR catalysts showed random fragment production from each ring-opening surface species. The selectivity depended on the reaction temperature, hydrogen pressure, and catalyst preparation. Changes in metal loading and pretreatment can cause interconversion between the two forms of Rh. Since the changes in TPR and catalytic behavior with metal loading and pretreatment were parallel, the changes in product distribution were ascribed to different morphologies of Rh particles. The results agreed well with earlier assumptions that selective ring opening involves an associative flat-lying intermediate that can be a common surface intermediate for single and multiple C-C bond cleavage.
1-Hexene Oligomerization in Liquid, Vapor, and Supercritical Phases over Beidellite and Ultrastable Y Zeolite Catalysts
Pater, Jerome P. G.,Jacobs, Pierre A.,Martens, Johan A.
, p. 477 - 482 (1998)
1-Hexene was oligomerized at 200°C and a pressure of 5 MPa in a down-flow fixed-bed tubular reactor filled with beidellite or ultrastable Y zeolite catalysts. Vapor, liquid, and supercritical states of the reacting hydrocarbons in the reactor tube were established by using propane, pentane, octane, and dodecane as solvents. The initial activity, stability with operation time, and selectivity are very dependent on the physical state of the hydrocarbons. Highest activity and stability are reached in the liquid phase using octane and dodecane solvent. The chain length of the solvent has a strong influence on the deactivation of the catalyst, on the oligomerization selectivity and on the formation of C6 saturates and cracked products.
Preparation and catalytic performance of a novel organometallic CoH/Hβ catalyst for: n -hexane isomerization
Zhang, Mei,Wang, Congcong,Zhang, Chao,Cai, Tingting,Zhu, Lijun,Xia, Daohong
, p. 15646 - 15653 (2020/10/22)
As a novel alkane isomerization catalyst, namely CoH/Hβ, was prepared by the reduction of CoH(P(OPh)3)4, which was pre-impregnated on Hβ as support. The as-prepared CoH/Hβ catalyst was structurally compared with CoH(P(OPh)3)4, CoH(P(OPh)3)4/Hβ via FT-IR, TPR, SEM, XRD and other techniques. The results show that the new organometallic hydride catalyst was synthesized successfully and exhibited excellent catalytic performance for the isomerization of n-hexane. For the best performance of the CoH/Hβ catalyst, the optimal catalytic reaction temperature, pressure, space velocity, and hydrogen/oil molar ratio were 300 °C, 2.0 MPa, 1.0 h-1, and 4.0, respectively, in the isomerization process of n-hexane. Under the optimal reaction conditions, the conversion of n-hexane, the yield of isomerization, and the selectivity towards iso-paraffins were 80.2%, 63.0%, and 78.6%, respectively. This performance is mainly attributed to the new structure of Co-H hydride in the CoH/Hβ catalyst, which has strong hydrogenation/dehydrogenation activity in the isomerization of n-hexane. This journal is
Mechanistic Insight into Synergistic Catalysis of Olefin Hydrogenation by a Hetero-Dinuclear RuII-CoII Complex with Adjacent Reaction Sites
Hong, Dachao,Ohgomori, Yuji,Shimoyama, Yoshihiro,Kotani, Hiroaki,Ishizuka, Tomoya,Kon, Yoshihiro,Kojima, Takahiko
supporting information, p. 11284 - 11288 (2019/09/03)
We have designed and synthesized a hetero-dinuclear RuII-CoII complex with a dinucleating ligand inspired by hetero-dinuclear active sites of metalloenzymes. A synergistic effect between the adjacent RuII and CoII sites has been confirmed in catalytic olefin hydrogenation by the complex, exhibiting a much higher turnover number than those of mononuclear RuII or CoII complexes as the components. A RuII-hydrido species was detected by 1H NMR and electrospray ionization (ESI)-time-of-flight (TOF)-MS measurements as an intermediate to react with olefins, and CoII-bound methanol was suggested to act as a proton source.
Physicochemical and Catalytic Properties of Ni,H/ZSM-5 and Ni,H/ZSM-5–Binder Catalysts Prepared in the Absence and in the Presence of Binder
Grzechowiak, J. R.,Jaroszewska, K.,Masalska, A.
, p. 851 - 861 (2020/02/21)
Physicochemical and catalytic properties of H/ZSM-5 and Ni,H/ZSM-5 along with Ni,H/ZSM-5–Al2O3 (1 : 1) systems were examined. The systems with a binder were prepared by two different methods of mixing zeolite with aluminum hydroxide. The samples were characterized by N2 sorption (at 77 K), X-ray diffraction, 27Al magic-angle spinning (MAS) NMR spectroscopy, temperature-programmed desorption of ammonia and adsorption of pyridine. Preparation of the zeolite catalyst with aluminium hydroxide was made by two methods: (1) mixing of powders and (2) combining appropriate pastes. Regardless of the method used for mixing there was no blocking of zeolite channels by aluminum oxide. The method of mixing zeolite with aluminium hydroxide powders promotes migration of aluminum from aluminum hydroxide/oxide to the zeolite framework. The results of n-hexane conversion showed that with Ni,H/ZSM-5 a slightly lower conversion than with H/ZSM-5 catalyst was observed that can be explained by a reduced yield of cracking products. Ni,H/ZSM-5–Al2O3 (1 : 1) catalytic systems were insignificantly less efficient in n-hexane transformation than alumina free samples but at the same time they were less selective towards hydrocarbons with boiling temperatures higher than this of n-hexane, precursors of carbonaceous deposits.
