1640-89-7Relevant academic research and scientific papers
The transformations of toluene on alumina and bifunctional catalysts
Masloboishchikova,Khelkovskaya-Sergeeva,Bogdan,Vasina,Kustov
, p. 551 - 556 (2006)
The activity of Pt, Rh, and Ni catalysts deposited on Al2O 3 and tungsten-containing catalysts 20% H4SiW 12O40/ZrO2 and 15% WOx/ZrO 2 in the hydrogenation of toluene and toluene ring opening and isomerization in the presence of hydrogen was studied. Under experimental conditions (160-360°C, 2.2 MPa), the main reactions on Rh/Al 2O3 were the hydrogenation of toluene into methylcyclohexane, hydrogenolysis into isoheptanes, and hydrocracking into alkanes C1-C6. On Pt, Rh, and Ni catalysts on carriers with strong acid properties, the isomerization of the six-membered into five-membered ring followed by hydrogenolysis (hydrocracking) of alkylcyclopentanes occurred. The yield of heptane isomers, however, did not exceed 13%. The activity of Pt and Rh catalysts on a high-acidity carrier (WOx/ZrO2) in hydrocracking was much higher than that of catalysts based on deposited heteropoly acid. The yields of hydrogenolysis (hydrocracking) products on Ni/WOx/ZrO2 were much lower than on Pt(Rh)/WOx/ZrO2. The highest yield of ring opening products (isoheptanes and n-heptane) was obtained with layered loading of two catalysts; it reached 58 wt % at 300°C and a 2.2 MPa pressure, which was 4.5 and 2 times higher than the yield obtained on Ni-Pt/WOx/ZrO 2 and 2% Rh/Al2O3 catalysts. Hydrodemethylation was not the main direction of toluene transformations on any of the catalysts studied. Pleiades Publishing, Inc., 2006.
Reaction Pathways of 1-Cyclohexyloctane in Admixture with Dodecane on Pt/H-ZSM-22 Zeolite in Three-Phase Hydroconversion
Arroyo, J. A. Munoz,Thybaut, J. W.,Marin, G. B.,Jacobs, P. A.,Martens, J. A.,Baron, G. V.
, p. 29 - 40 (2001)
Isomerization and hydrocracking of a mixture of 1-cyclohexyloctane and dodecane were performed on Pt/H-ZSM-22 in a three-phase Robinson Mahoney reactor with complete internal mixing (T = 523-543 K, P=7-8 MPa, H2/HC =5). The reaction products from 1-cyclohexyloctane were analyzed in detail and compared with those obtained in the absence of dodecane in a fixed-bed vapor-phase reactor (T = 460 K, P = 0.45 MPa, H2/HC = 450). In the presence of dodecane, the main reaction pathway involved contraction of the six-membered ring to a five-membered ring with concomitant elongation of the octyl chain by one carbon. Subsequently, the nonyl chain underwent methyl branching at carbon positions far from the ring. Methyl branching rearrangements of the cyclohexane ring of 1-cyclohexyloctane were suppressed in the presence of dodecane. In the reaction product fraction of heptylmethylcyclohexanes, all cis-trans and positional isomers were formed except the 1,1'-heptylmethylcyclohexane isomer. The isomer distributions were explained with pore mouth and key-lock catalysis. Pt/H-ZSM-22 did not favor the paring reaction. The distribution of cracked products, and especially the abundant formation of alkylcyclopentanes, was in agreement with cracking through β-scission in the chain rather than by ring dealkylation typical of the paring reaction. Ring opening in 1-cyclohexyloctane and its isomers is a less important side reaction.
Toluene hydrogenation at low temperature using a molybdenum carbide catalyst
Frauwallner, María-Laura,López-Linares, Francisco,Lara-Romero,Scott, Carlos E.,Ali, Vieman,Hernández, Eumir,Pereira-Almao, Pedro
, p. 62 - 70 (2011)
A molybdenum carbide catalyst prepared with a novel methodology and its toluene hydrogenation activity tested at temperatures within 423-598 K and 2.76 MPa is here reported. Almost 100% hydrogenation was achieved at 473 K with this catalyst. The activation energy was 58.1 kJ/mol with a zero-order reaction for toluene concentration, illustrating a behavior comparable to that of noble metals. Additional catalyst formulations were tested and their activities compared between them. XRD and Raman characterization of the catalysts allowed identification of several species in the newly synthesized catalyst, namely fcc-Mo2C and MoO2. Crown Copyright
Fabricating nickel phyllosilicate-like nanosheets to prepare a defect-rich catalyst for the one-pot conversion of lignin into hydrocarbons under mild conditions
Cao, Meifang,Chen, Bo,He, Chengzhi,Ouyang, Xinping,Qian, Yong,Qiu, Xueqing
supporting information, p. 846 - 857 (2022/02/09)
The one-pot conversion of lignin biomass into high-grade hydrocarbon biofuels via catalytic hydrodeoxygenation (HDO) holds significant promise for renewable energy. A great challenge for this route involves developing efficient non-noble metal catalysts to obtain a high yield of hydrocarbons under relatively mild conditions. Herein, a high-performance catalyst has been prepared via the in situ reduction of Ni phyllosilicate-like nanosheets (Ni-PS) synthesized by a reduction-oxidation strategy at room temperature. The Ni-PS precursors are partly converted into Ni0 nanoparticles by in situ reduction and the rest remain as supports. The Si-containing supports are found to have strong interactions with the nickel species, hindering the aggregation of Ni0 particles and minimizing the Ni0 particle size. The catalyst contains abundant surface defects, weak Lewis acid sites and highly dispersed Ni0 particles. The catalyst exhibits excellent catalytic activity towards the depolymerization and HDO of the lignin model compound, 2-phenylethyl phenyl ether (PPE), and the enzymatic hydrolysis of lignin under mild conditions, with 98.3% cycloalkane yield for the HDO of PPE under 3 MPa H2 pressure at 160 °C and 40.4% hydrocarbon yield for that of lignin under 3 MPa H2 pressure at 240 °C, and its catalytic activity can compete with reported noble metal catalysts.
PROCESS FOR SELECTIVE RING OPENING OF CYCLIC HYDROCARBONS
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Paragraph 0057; 0060-0067, (2020/04/29)
PURPOSE: A process for ring opening is provided to obtain improved conversion ratio and selectivity in comparison with the case of using hydrogen as a reducing agent. CONSTITUTION: A cyclic hydrocarbon and a reducing agent are provided as supplying materials. The supplying materials are transferred into a reactor (5) and reacted under the presence of a catalyst. A product is separated from the effusion of reaction zone. The catalyst is a heterogeneous catalyst having both acid site and metallic component. The product is obtained by evaporating and heating a mixture containing 100 parts by weight of porous molecular sieve and 0.01-20 parts by weight of water soluble metallic salt. The cyclic hydrocarbon is a naphthene group cyclic hydrocarbon which is pentagonal or hexagonal compound, or an alkyl derivative thereof selected from cyclopentane and cyclohexane. The alkyl derivative is methyl, ethyl, profile, butyl, isopropyl or an isobutyl derivative.
Modification of the catalytic properties of MoO2-x(OH) y dispersed on TiO2 by Pt and Cs additives
Al-Kandari,Mohamed,Al-Kharafi,Zaki,Katrib
experimental part, p. 298 - 305 (2012/05/20)
Addition of 5% Pt or alkali metals such as K or Cs each separately to the bifunctional MoO2-x(OH)y catalyst results in modification of the chemical structure of this system, especially in the case of alkali metals. A new MoO2-x(OA)y, AK, Cs, monofunctional structure having only metallic properties is formed. In the case of Cs for example, the MoOCs bond formation takes place in the course of the reduction process of MoO3 to MoO2 by hydrogen hinders the acidic Br?nsted MoOH formation, which usually is formed in this system. Characterization by surface XPS-UPS, ISS and FT-IR spectroscopic techniques as well as catalytic activity carried out at the same experimental conditions confirm the presence of this monofunctional MoO2-x(OCs)y system. On the contrary, platinum addition enhances the metallic character of the MoO2-x(OH)y bifunctional system in terms of slight improvement in the conversion of 1-heptene and n-heptane as well as dehydrogenation of methylcyclohexane to toluene.
A novel iron complex for cross-coupling reactions of multiple C-Cl bonds in polychlorinated solvents with grignard reagents
Gartia, Yashraj,Pulla, Sharon,Ramidi, Punnamchandar,Farris, Carolina Costa,Nima, Zeid,Jones, Darin E.,Biris, Alexandru S.,Ghosh, Anindya
, p. 1397 - 1404 (2013/01/15)
A novel iron(III) complex (2) of a pincer ligand [1, N2,N6-bis(2,6- diisopropylphenyl)pyridine-2,6-dicarboxamide] was developed and used for remediation of polychlorinated solvents via sp3-sp3 coupling of Grignard reagents with C-Cl bonds. The use of an iron catalyst for such coupling reactions is highly desirable due to its greener and more economical nature. Complex 2 was characterized using various spectroscopic techniques: electrospray ionization mass spectrometer (ESI-MS, m/z 575.1), cyclic voltammetry (E 1/2, 0.03 V and ΔE, 0.97 V), and ultraviolet visible (UV/Vis) spectroscopic techniques. The iron(III) complex showed efficient activation of multiple C-Cl bonds and catalyzing C-C coupling of polychlorinated alkyl halides, such as dichloromethane (CH2Cl2), chloroform (CHCl3), and carbon tetrachloride (CCl4), with various Grignard reagents under ambient reaction conditions. Complex 2 showed exceptional activity with reactions approaching near completion in about 5 min. With the required catalyst loading as low as 0.2 mol%, considerably high turnover numbers (TON = 483) and turnover frequency (TOF = 5,800 h-1) were obtained. None of the products detected during the reaction contained any chlorine, indicating an efficient dechlorination method while synthesizing products of synthetic and commercial interest. Interestingly, the catalyst was capable of replacing all chlorine atoms in each polychlorinated solvent under the investigations with high conversion. Springer Science+Business Media, LLC 2012.
Cross coupling reactions of multiple CCl bonds of polychlorinated solvents with Grignard reagent using a pincer nickel complex
Gartia, Yashraj,Nasini, Udaya Bhasker,Ghosh, Anindya,Biswas, Abhijit,Stadler, Matthew
, p. 322 - 327,6 (2020/07/30)
The nickel(II) complex of a bulky pincer-type ligand, N,N′-bis(2,6- diisopropylphenyl)-2,6-pyridinedicarboxamido, was examined for sp 3-sp3 coupling of Grignard reagents with polychlorinated solvents. The nickel(II) complex catalyzed CC coupling of polychlorinated alkyl halides, such as dichloromethane (CH2Cl2), chloroform (CHCl3), and carbon tetrachloride (CCl4), with various Grignard reagents. The effective activation of multiple CCl bonds proceeded under ambient reaction conditions and within a short time (20 min). This catalyst displays the highest activity yet reported for this reaction type, with catalyst loading as low as 0.4 mol% and turnover frequency (TOF) as high as 724 h-1. The catalyst is capable of replacing all chlorine atoms with CC bond formations for all of the polychlorinated solvents under investigation. The catalytic process could prove to be an efficient method of remediation of toxic polychlorinated solvents while generating synthetically and commercially important chemicals.
Carbon-carbon coupling of C(sp3)-F bonds using alumenium catalysis
Gu, Weixing,Haneline, Mason R.,Douvris, Christos,Ozerov, Oleg V.
experimental part, p. 11203 - 11212 (2009/12/05)
Dialkylalumenium cation equivalents coupled with the hexabromocarborane anion function as efficient and long-lived catalysts for alkylation of aliphatic C-F bonds (alkylative defluorination or AlkDF) by alkylaluminum compounds. Only C(sp3)-F bo
Process for Reacting an Aromatic Hydrocarbon in the Presence of Hydrogen
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Page/Page column 15-18, (2009/01/20)
Processes comprising: providing a starting material comprising one or more aromatic hydrocarbons, and having an aromatic sulfur compound content and a total sulfur content; reducing the aromatic sulfur compound content and the total sulfur content in the starting material; and hydrogenating the one or more aromatic hydrocarbons in the presence of a supported ruthenium catalyst and hydrogen.
