Loading...
Search for:
cyclohexene
0.01 seconds
A novel efficient magnetic core-zeolitic shell nanocatalyst system: Preparation, characterization and activity
, Article Chemical Papers ; Volume 69, Issue 6 , 2015 , Pages 856-863 ; 03666352 (ISSN) ; Vossoughi, M ; Janfada, B ; Sharif University of Technology
De Gruyter Open Ltd
2015
Abstract
Analcime shell-nickel ferrite core microspheres were decorated with Pd and Pt nanoparticles with the aid of an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6). The samples thus prepared were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), nitrogen adsorption-desorption isotherms, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) methods. The XRD patterns confirmed the growth of a zeolitic layer on the surface of the magnetic cores. The thermogravimetric analysis (TGA) curve clearly indicated the thermal decomposition of the loaded IL, which confirmed the presence of...
One pot oxidative cleavage of cyclohexene to adipic acid using silver tungstate nano-rods in a Brønsted acidic ionic liquid
, Article RSC Advances ; Volume 5, Issue 40 , Mar , 2015 , Pages 31298-31302 ; 20462069 (ISSN) ; Mahmoodi Hashemi, M ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
A green and facile method for oxidation of cyclohexene to adipic acid is introduced using 30% H2 O2 as oxidant. The catalytic system comprises small amounts of Ag2 WO4 nano-rods and a Brønsted acidic ionic liquid (1,2-dimethyl-3-dodecylidazolium hydrogensulfate)
Oxovanadium(IV) complexes as homogeneous catalyst-aerobic epoxidation of olefins
, Article Applied Catalysis A: General ; Volume 278, Issue 2 , 2005 , Pages 263-267 ; 0926860X (ISSN) ; Boghaei, D. M ; Sarvestani, A. H ; Salimi, A ; Sharif University of Technology
2005
Abstract
The novel N2O2 unsymmetrical tetradentate Schiff bases complexes are used as catalysts for the selective aerobic oxidation of cyclohexene. In general, conversion percentages decrease with increasing ΔEp and decreasing Eredox 0′. Catalytic activity increases with decrease of the number of electron-donating groups and the catalytic selectivity varies according to the types of substituents in the ligands. The catalytic system described here is an inexpensive method for selective oxidation of olefins, with advantages of high activity, selectivity, re-usability and short reaction times. Analysing GC and redox potential results shows a moderate correlation between selectivity and activity. © 2004...
Dual catalytic function of the task-specific ionic liquid: Green oxidation of cyclohexene to adipic acid using 30% H2O2
, Article Chemical Engineering Journal ; Volume 221 , April , 2013 , Pages 254-257 ; 13858947 (ISSN) ; Hashemi, M. M ; Sharif University of Technology
2013
Abstract
The sole industrial process which currently used for adipic acid production is nitric acid oxidation of either cyclohexanol or cyclohexanol/cyclohexanone mixture. Emission of greenhouse nitrous oxide (N2O) gas from this process strongly contributes to global warming, resulting in acid rain and ozone depletion. Herein, we report a catalytic application of a novel dual task-specific ionic liquid (an ionic liquid with two catalytic functions) for oxidation of cyclohexene to adipic acid using 30% hydrogen peroxide. The catalyst showed desirable activity toward oxidation of cyclohexene and some cyclic olefins to produce their corresponding dicarboxylic acids
Kinetic Study of Heterogeneous and Homogeneous Catalytic Reactions in Molecular and Ionic Solvents and Their Mixtures
, Ph.D. Dissertation Sharif University of Technology ; Gholami, Mohammad Reza (Supervisor) ; Habibi Yangjeh, Aziz (Supervisor)
Abstract
Solvatochromic parameters (ETN: normalized polarity parameter, π*: dipolarity/polarizability, β: hydrogen-bond acceptor basicity, α: hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (2-hydroxyethylammonium formate) at 25 ◦C. The applicability of nearly ideal combined binary solvent/Redlich-Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition. Solute-solvent and solvent-solvent interactions were applied to interpret the results. Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/Al2O3, was carried out in...
Synthesis of Pt- Nanoparticle in Ionic Liquid Coated on Alumina and the Investigation of the Nature and Thickness of Ionic Liquid on Catalyst Pt / Al2O3
, M.Sc. Thesis Sharif University of Technology ; Gholami, Mohammad Reza (Supervisor)
Abstract
In this project ionic liquid and there mixtures were coated on Pt/ Al2O3 , the prepared catalyst were characterization by SEM, BET and XRD techniques.In the first stage the effect of the coated ionic liquid on the Pt/Al2O3 were investigated, on the rate of C=C hydrogenation. in the second stage effect of the thickness of ionic liquids on the rate of the cyclohexene hydrogenation were studied. Result revelad that by increasing the ionic liquid polarity, the reaction rate increased. Also the reaction rate decreased by increasing the thickness of ionic liquid
Design of silica supported task-specific ionic liquid catalyst system for oxidation of cyclohexene to adipic acid with 30% H 2O 2
, Article Catalysis Communications ; Volume 26 , September , 2012 , Pages 54-57 ; 15667367 (ISSN) ; Hashemi, M. M ; Shakourian Fard, M ; Sharif University of Technology
Elsevier
2012
Abstract
1-Butyl-3-methylimidazolium tungstate ([BMIm] 2WO 4) ionic liquid supported onto silica sulphamic acid demonstrated desirable performance for oxidation of cyclohexene to adipic acid. Simple experimental procedure, easy product isolation, catalyst recovery and reusability are some attractive features of this protocol
Immobilization of a molybdenum complex on the surface of magnetic nanoparticles for the catalytic epoxidation of olefins
, Article New Journal of Chemistry ; Volume 40, Issue 2 , 2016 , Pages 1580-1586 ; 11440546 (ISSN) ; Moradi Shoeili, Z ; Bagher Zadeh, M ; Akbayrak, S ; Özkar, S ; Sharif University of Technology
Royal Society of Chemistry
Abstract
Novel organic-inorganic hybrid heterogeneous nanocatalysts were obtained by covalent anchoring of a molybdenum(vi) complex of salicylidene 2-picoloyl hydrazine, MoO2(sal-phz)(CH3OH), (1) on the surface of magnetic nanoparticles functionalized by one of two routes: in the first method, the surface of magnetic nanoparticles is directly modified with 3-chloropropyltrimethoxysilane yielding 1A. In the second method, magnetic nanoparticles were silica-coated with tetraethoxysilane and then with 3-chloropropyltrimethoxysilane yielding the intermediate 2B. Then complex 1 was grafted on the surface of 1A or 2B through covalent interaction yielding 2A or 3B, respectively. The nanocatalysts 2A and 3B...
Solvent effects on the reaction rate and selectivity of synchronous heterogeneous hydrogenation of cyclohexene and acetone in ionic liquid/alcohols mixtures
, Article Journal of Molecular Catalysis A: Chemical ; Volume 306, Issue 1-2 , 2009 , Pages 11-16 ; 13811169 (ISSN) ; Habibi Yangjeh, A ; Gholami, M. R ; Sharif University of Technology
2009
Abstract
Synchronous heterogeneous catalytic hydrogenation of cyclohexene and acetone, catalyzed by Pt/Al2O3, was carried out in solutions of 2-hydroxy ethylammonium formate (a room temperature ionic liquid, RTIL) with ethanol and propan-1-ol at 25 °C. Rate constants and selectivity of the reaction (relative to cyclohexene hydrogenation) increase with mole fraction of the ionic liquid (IL). The reactants tendency to the catalyst surface increases by addition of the ionic liquid and thus the reaction rate increases, especially for cyclohexene hydrogenation. Consequently the selectivity to cyclohexene hydrogenation was increased. Single-parameter correlations of log k vs. π* (dipolarity/polarizibility)...
Characterization of volatile components of Iranian saffron using factorial-based response surface modeling of ultrasonic extraction combined with gas chromatography-mass spectrometry analysis
, Article Journal of Chromatography A ; Volume 1216, Issue 33 , 2009 , Pages 6088-6097 ; 00219673 (ISSN) ; Parastar, H ; Ebrahimi Najafabadi, H ; Sharif University of Technology
2009
Abstract
The volatile components of Iranian saffron were extracted using ultrasonic solvent extraction (USE) technique and then were separated and detected by gas chromatography-mass spectrometry (GC-MS). Variables affecting the extraction procedure were screened by using a 25-1 fractional factorial design and among them; sample amount, solvent volume, solvent ratio and extraction time were optimized by applying a rotatable central composite design (CCD). The optimum values of factors were: 2.38 g sample, 29.04 mL solvent, 69.23% MeOH solvent ratio and 71.8 min for the extraction time. Forty constituents were identified for Iranian saffron by GC-MS representing 90% of the total peak area. The major...
Cyclohexene oxidation catalyzed by flower-like core-shell Fe3O4@Au/metal organic frameworks nanocomposite
, Article Materials Chemistry and Physics ; Volume 213 , July , 2018 , Pages 472-481 ; 02540584 (ISSN) ; Gholami, M. R ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this study, Fe3O4@Au/metal-organic frameworks (Fe3O4@Au/MOF) nanocomposite with flower-like core-shell structure was successfully synthesized via a hydrothermal route. The as-prepared catalyst was characterized using different techniques such as FT-IR, XRD, TEM, EDX, VSM, TGA, BET, and ICP. This nanocomposite exhibited an excellent catalytic performance in selective oxidation of cyclohexene to 2-cyclohexene-1-one by using molecular oxygen as green oxidant. The influence of reaction conditions including, pressure of molecular oxygen, temperature, time, solvent, and amount of catalyst on conversion and selectivity of products were evaluated. The activation energy (Ea) of the reaction was...
Supported PtxPd1-x bimetallic nanoparticles on ionic liquid-functionalized SiO2@graphene oxide nanocomposite and its application as an effective multiphasic catalyst
, Article Applied Catalysis A: General ; Volume 579 , 2019 , Pages 30-43 ; 0926860X (ISSN) ; Giannakis, S ; Gholami, M. R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this work, PtxPd1-x (x = 0, 0.5, and 1)nanoparticles (NPs)were synthesized on the surface of SiO2@graphene oxide which covered by 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6)ionic liquid (IL)layer. FT-IR spectroscopy, zeta potential, CHN elemental analysis, XRD, XPS, SEM, EDX, TEM, TGA, BET, and ICP-AES techniques were applied for the characterization of the multiphasic catalyst. The as-prepared nanocomposite was used as an effective heterogeneous catalyst for the oxidation of cyclohexene by molecular oxygen, as a green oxidant. Different experimental conditions such as oxygen pressure, reaction time, reaction temperature and amount of catalyst were investigated in this...
Self-modeling curve resolution techniques applied to comparative analysis of volatile components of Iranian saffron from different regions
, Article Analytica Chimica Acta ; Volume 662, Issue 2 , 2010 , Pages 143-154 ; 00032670 (ISSN) ; Parastar, H ; Ebrahimi Najafabadi, H ; Sharif University of Technology
Abstract
Volatile components of saffron from different regions of Iran were extracted by ultrasonic-assisted solvent extraction (USE) and were analyzed by gas chromatography-mass spectrometry (GC-MS). Self-modeling curve resolution (SMCR) was proposed for resolving the co-eluted GC-MS peak clusters into pure chromatograms and mass spectra. Multivariate curve resolution-objective function minimization (MCR-FMIN) and multivariate curve resolution-alternating least square (MCR-ALS) were successfully used for this purpose. The accuracy of the qualitative and quantitative results was improved considerably using SMCR techniques. Comparison of the results of saffron from different regions of Iran showed...