Search for: heterogeneous-catalyst
Total 54 records
Thermokinetic study of Fischer-Tropsch synthesis on Fe2Cu 1 and FeCu surfaces with comparison to Fe(110) and Cu(111) catalysts by the UBI-QEP method, Article Journal of the Iranian Chemical Society ; Vol. 11, issue. 5 , 2014 , pp. 1305-1310 ; SSN: 1735-207X ; Sajjadifar, S ; Sharif University of Technology
The purpose of this study is to predict the activation barriers and enthalpy for elementary steps in the process of Fischer-Tropsch (F-T) on the surfaces of Fe(110), Cu(111) and Fe/Cu alloys catalyst using "Unity Bond Index-Quadratic Exponential Potential" method aimed at predicting the activity and selectivity on the basis of energy criteria. The elementary steps, such as dissociation of CO, hydrogenation of carbidic carbon, C-C chain growth by insertion of CH2 versus CO into the metal-alkyl bonds, and chain termination, which lead to hydrocarbons (alkanes versus α-olefins) or oxygenates are discussed in detail. The results show that metallic Fe(110) is necessary to produce the carbidic...
Manganese and cobalt-terephthalate metal-organic frameworks as a precursor for synthesis of Mn
Inorganic Chemistry Communications
; Zare, M
; Bagherzade, M
Sharif University of Technology
2O 3, Mn 3O 4 and Co 3O 4 nanoparticles: Active catalysts for olefin heterogeneous oxidation
The thermal decomposition of manganese and cobalt-terephthalate Metal-Organic Framework precursors was utilized as a synthetic route for fabrication of Co
3O 4, Mn 3O 4 and Mn 2O 3 nanoparticles. The prepared metal oxide nanoparticles of Co 3O 4, Mn 3O 4 and Mn 2O 3 possess average size diameter of 40, 60 and 80 nm respectively. The findings demonstrate that spinel structure nanoparticles of Co 3O 4 and Mn 3O 4 exhibit efficient catalytic activity toward heterogeneous olefin epoxidation in the presence of tert-butyl hydroperoxide. In...
Synthesis, characterization, and catalytic activity of supported molybdenum Schiff base complex as a magnetically recoverable nanocatalyst in epoxidation reaction, Article Journal of Coordination Chemistry ; Volume 69, Issue 4 , 2016 , Pages 668-677 ; 00958972 (ISSN) ; Zare, M ; Bagherzadeh, M ; Ozkar, S ; Akbayrak, S ; Sharif University of Technology
Taylor and Francis Ltd 2016
A heterogeneous nanocatalyst was prepared via covalent anchoring of dioxomolybdenum(VI) Schiff base complex on core-shell structured Fe3O4@SiO2. The properties and the nature of the surface-fixed complex have been identified by a series of characterization techniques such as SEM, EDX, XRD, TGA, FT-IR, and VSM. The synthesized hybrid material was an efficient nanocatalyst for selective oxidation of olefins to corresponding epoxides with t-BuOOH in high yields and selectivity. The catalyst could be conveniently recovered by applying an external magnetic field and reused several times without significant loss of efficiency. © 2016 Taylor and Francis
A green and efficient route for P − S − C bond construction using copper ferrite nanoparticles as catalyst: a TD-DFT study, Article Phosphorus, Sulfur and Silicon and the Related Elements ; 26 October , 2020 ; Daneshfar, M ; Azaryan, R ; Sharif University of Technilogy
Taylor and Francis Ltd 2020
Magnetic nanoparticles of CuFe2O4 were applied as catalyst system for one-pot thiophosphate synthesis via the reaction of aryl sulfonyl chlorides with H-phosphonates under conventional heating conditions. This is an extremely efficient and green method for thiophosphate synthesis under base- and solvent-free conditions. Various thiophosphates were obtained in good to excellent yields under the optimized reaction conditions in a short time. The catalyst can be easily recycled from the reaction by an external magnetic field and reused for the next run. In this study, TD-DFT B3LYP/6-31 + G(d) calculations are in good accord with the experimental results. A comparison between experimental and...
Synthesis, characterizations and catalytic studies of a new two-dimensional metal-organic framework based on Co-carboxylate secondary building units, Article Journal of Solid State Chemistry ; Volume 223, March , 2014 , Pages 32-37 ; ISSN: 00224596 ; Ashouri, F ; Dakovic, M ; Sharif University of Technology
A metal-organic framework [Co3(BDC)3(DMF)2(H2O)2] was synthesized and structurally characterized. X-ray single crystal analysis revealed that the framework contains a 2D polymeric chain through coordination of 1,4-benzenedicarboxylic acid linker ligand to cobalt centers. The polymer crystallize in monoclinic P21 /n space group with a=13.989(3) Å, b=9.6728(17) Å, c=16.707(3) Å, and Z=2. The polymer features a framework based on the perfect octahedral Co-O6 secondary building units. The catalytic activities of [Co3(BDC)3(DMF)2(H2O)2]n for olefins oxidation was conducted. The heterogeneous catalyst could be facilely separated from the reaction mixture, and reused three times without significant...
Supported Pd nanoparticles on Mn-based metal-organic coordination polymer: Efficient and recyclable heterogeneous catalyst for Mizoroki-Heck cross coupling reaction of terminal alkenes, Article Inorganic Chemistry Communications ; Vol. 44 , 2014 , Pages 10-14 ; ISSN: 13877003 ; Ashouri, F ; Hashemi, L ; Morsali, A ; Sharif University of Technology
Supported palladium nanoparticles on Mn-carboxylate coordination polymer (Pd/MnBDC) were prepared using solution impregnation method. This new catalyst was characterized by XRD, SEM, TEM, EDX, XPS, FTIR and TGA analysis. The Pd/MnBDC exhibits efficient catalytic activity for the Mizoroki-Heck coupling reaction between iodobenzene and either aromatic or aliphatic terminal alkenes and reuses up to four runs without significant loss of activities
Synthesis, structural characterization and application of a 2D coordination polymer of Mn-terephthalate as a heterogeneous catalyst for olefin oxidation, Article Polyhedron ; Volume 69 , 17 February , 2014 , Pages 167-173 ; ISSN: 02775387 ; Ashouri, F ; Crossed D Signakovic, M ; Sharif University of Technology
A metal-organic coordination polymer of [Mn3(1,4- benzenedicarboxylate)3(DMF)4] ([Mn3(BDC) 3(DMF)4]n) was synthesized and characterized by IR spectra, elemental analysis (CHN), thermal gravimetric analysis (TGA) and single crystal X-ray diffraction analysis. The structure of [Mn 3(BDC)3(DMF)4]n is a 2D-periodic framework based on Mn(II)-terephthalate secondary building units (SBUs). The catalytic oxidation of various olefins was effectively carried out with [Mn 3(BDC)3(DMF)4]n. Moreover, the influence of key reaction parameters, including the solvents, reaction temperatures and nature of oxidant were studied. The optimized conditions were achieved by TBHP as the efficient oxidant in...
The effect of framework functionality on the catalytic activation of supported Pd nanoparticles in the Mizoroki–Heck coupling reaction, Article Comptes Rendus Chimie ; Volume 20, Issue 2 , 2017 , Pages 107-115 ; 16310748 (ISSN) ; Zare, M ; Bagherzadeh, M ; Sharif University of Technology
Elsevier Masson SAS 2017
Palladium nanoparticles (Pd-NPs) were supported on functional and nonfunctional Co-coordination polymers (Pd/CoBDCNH2 and Pd/CoBDC). Advanced analytical techniques revealed that Pd-NPs are supported on the external surface of the polymer framework and the functionalized framework possesses effective influence to prevent Pd-NP aggregation. Supported Pd-NPs were effectively applied as heterogeneous recyclable catalysts in the Mizoroki–Heck C–C cross coupling reactions of iodobenzene and either aromatic or aliphatic terminal alkenes. Catalytic results exhibited that highly dispersed Pd-NPs with low loading (1%) on the functional polymer (Pd/CoBDCNH2) are more effective than aggregated Pd-NPs...
Preparation of Nitrogen Rich Magnetic Nanocomposite for Immobilization of Transition Metals and Investigation of their Catalytic Activity in Organic Reactions, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali ; Matloubi, Firouz
In this thesis, heterogeneous magnetic catalysts immobilize have been designed and synthesized in a triazine polymer support. Triazine polymeric support increases the amount of nitrogen due to their high levels of nitrogen, which in turn reduces the amount of catalyst consumed and reduces metal waste and increases catalyst activate. Melamine and TCT from the triazine family are used because of the ability to form hydrogen bonds, chelate with metals, and the interaction of π-π as an appropriate ligand for stabilizing metals on substrates. In this thesis, various nitrogen-rich polymers based on triazines in the presence of magnetic nanoparticles coated with silica and their compositions with...
Gadolinium triflate immobilized on magnetic nanocomposites as recyclable Lewis acid catalyst for acetylation of phenols, Article Nanoscience and Nanotechnology Letters ; Vol. 6, issue. 4 , 2014 , p. 309-313 ; Kim, A ; Shokouhimehr, M ; Sharif University of Technology
The acetylation of phenols with acetic anhydride proceeded in excellent yields when it was catalyzed by gadolinium triflate immobilized on magnetically recyclable nanocomposites. This heterogeneous catalyst provided high catalytic activity with low loading level (1 mol%), because the Lewis acid catalyst was grafted on the surface of the nanocomposites. The catalysts were also easily recovered from the reaction mixture using a magnet and reused for six consecutive cycles
Molybdenum liquid salts immobilized on ionic liquid-modified silica as efficient heterogeneous catalysts for sulfoxide reduction, Article Tetrahedron Letters ; Volume 54, Issue 29 , 2013 , Pages 3765-3768 ; 00404039 (ISSN) ; Ghazali Esfahani, S ; Sharif University of Technology
Two room temperature liquid salts containing molybdenum(VI), [BMIM] 2[MoO2(NCS)4] (1) and [DMIM] 2[MoO2(NCS)4] (2), were immobilized on ionic liquid-modified silica leading to materials which showed notable catalytic activity for the reduction of sulfoxides into sulfides with triphenylphosphine (PPh3). The molybdenum liquid salts immobilized on the supported ionic liquid phase could be reused at least for three catalytic cycles without significant loss of activity
Copper loaded cross-linked poly(ionic liquid): Robust heterogeneous catalyst in ppm amount, Article RSC Advances ; Volume 5, Issue 38 , 2015 , Pages 29609-29617 ; 20462069 (ISSN) ; Hosseini, S. H ; Matloubi Moghaddam, F ; Ayati, S. E ; Sharif University of Technology
Royal Society of Chemistry 2015
A novel heterogeneous copper catalyst was synthesized in which poly(1-vinyl imidazole-co-ionic liquid) was used as a solid heterogeneous support. The catalyst was readily synthesized in a large scale amount. The catalyst has a high loading level of copper ions and can be used in low weight percentages. The resulting catalyst was highly active in the preparation of triazoles by the Huisgen 1,3-dipolar cycloaddition method. In some cases the catalytic turnover number and frequency reached 70 002 and 3889 h-1, respectively. The catalyst was recycled many times without significant loss of activity. This journal is
Transesterification of canola oil to biodiesel using CaO/Talc nanopowder as a mixed oxide catalyst, Article Chemical Engineering and Technology ; Volume 40, Issue 10 , 2017 , Pages 1923-1930 ; 09307516 (ISSN) ; Kazemeini, M ; Bastan, F ; Sharif University of Technology
A series of heterogeneous catalysts including different molar ratios of CaO/talc was synthesized to study the transesterification reaction of canola oil and methanol under different reaction conditions. Characterization and kinetic results revealed that the activity of this catalyst was enhanced due to the increase of CaO/talc molar ratio value leading to an improvement in the biodiesel production. Moreover, the effect of various parameters on the activity of the undertaken catalysts was studied in order to determine the optimum process conditions. Leaching measurements and the durability of the CaO/talc catalyst under several reaction cycles were evaluated and proved it to be a stable...
Immobilized palladium nanoparticles on MNPs@A-N-AEB as an efficient catalyst for C-O bond formation in water as a green Solvent, Article Applied Organometallic Chemistry ; Volume 32, Issue 9 , 2018 ; 02682605 (ISSN) ; Eslami, M ; Sharif University of Technology
John Wiley and Sons Ltd 2018
Palladium nanoparticles immobilized on the magnetic nanoparticles@2-amino-N-(2-aminoethyl) benzamide (MNPs@A-N-AEB.Pd0) have been presented as an efficient, and reusable magnetically heterogeneous catalyst for the C-O coupling reaction, namely Ullmann condensation reactions in an aqueous medium. This heterogeneous catalyst shows superior reactivity for the C-O arylation of different aryl halide (chloride, bromide, and iodide) with phenol derivatives to afford the desired products in good to excellent yields within short reaction time. Moreover, the catalyst can be easily recovered and reused for seven runs without loss of catalytic activity. The catalyst was characterized by several...
Silver nanoparticles immobilized onto poly(4-vinylpyridine)-functionalized magnetic nanoparticles: a robust magnetically recyclable catalyst for oxidant-free alcohol dehydrogenation, Article Applied Organometallic Chemistry ; Volume 32, Issue 2 , February , 2018 ; 02682605 (ISSN) ; Shakourian Fard, M ; Talebloo, N ; Mahmoodi Hashemi, M ; Sharif University of Technology
John Wiley and Sons Ltd 2018
A heterogeneous and recyclable catalyst with a high loading of silver nanoparticles was synthesized via the silver nanoparticles being supported onto the surface of magnetic nanoparticles coated with poly(4-vinylpyridine). The synthesized catalyst was used in the dehydrogenation of alcohols to corresponding carbonyl compounds. A broad diversity of alcohols was converted into their corresponding carbonyl compounds in excellent yields. The catalyst was easily recovered by applying an external magnetic field and reused for seven reaction cycles without considerable loss of activity. The catalyst was fully characterized using various techniques. Copyright © 2017 John Wiley & Sons, Ltd
The selective aerobic oxidation of methylaromatics to benzaldehydes using a unique combination of two heterogeneous catalysts, Article Organic and Biomolecular Chemistry ; Volume 3, Issue 5 , 2005 , Pages 725-726 ; 14770520 (ISSN) ; Clark, J. H ; Karimi, B ; Macquarrie, D. J ; Sharif University of Technology
A unique combination of a supported cobalt complex and the first example of supported NHPI in acetic acid gives a surprisingly stable heterogeneous catalytic system for the selective aerobic oxidation of methylaromatics to benzaldehydes at atmospheric pressure. © The Royal Society of Chemistry 2005
Magnetic nanocomposite based on functionalized salep as a green support for immobilization of palladium nanoparticles: Reusable heterogeneous catalyst for Suzuki coupling reactions, Article Catalysis Communications ; Volume 97 , 2017 , Pages 27-31 ; 15667367 (ISSN) ; Motamedi, A ; Marvdashti, Z ; Hosseini, S. H ; Sharif University of Technology
Elsevier B.V 2017
The synthesis and catalytic behavior of palladium loaded magnetic nanocomposite based on natural polysaccharide salep modified with poly (amino pyridine) is described. The synthesized support is loaded with relatively large amounts of palladium ions (0.34mmol g−1). This is a simple, ecologically safe and cost-effective route for the preparation of the novel heterogeneous catalyst that shows high activity for Suzuki coupling reactions under remarkably mild conditions. Furthermore, the prepared catalyst is magnetically recovered and effectively reused for seven cycles of reactions without significant loss of its catalytic activity and loaded palladium nanoparticles. © 2017
Transesterification of waste cooking oil to biodiesel using KOH/γ-Al2O3 catalyst in a new two-impinging-jets reactor, Article Industrial and Engineering Chemistry Research ; Vol. 53, Issue. 31 , 2014 , Pages 12238-12248 ; ISSN: 08885885 ; Molaei Dehkordi, A ; Sharif University of Technology
In this article, the transesterification of waste cooking oil (WCO) to biodiesel fuel (BDF) has been studied using KOH loaded on millimetric γ-Al2O3 particles in a novel type of two-impinging-jets reactor (TIJR). The effects of various parameters such as KOH loading (wt %), catalyst loading, and methanol-to-oil molar ratio on the BDF yield were studied. The catalyst particles with a KOH loading of 25 wt % at appropriate reaction conditions (i.e., catalyst loading = 4 wt % and methanol-to-oil molar ratio = 15:1) and at 65 °C were used in the TIJR. The influences of various operating and design parameters such as jet Reynolds number value, feed flow rate, jet diameter, and the internozzle...
Interaction of ionic liquids with the surface of silica gel using nanocluster approach: A combined density functional theory and experimental study, Article Journal of Physical Organic Chemistry ; Vol. 27, issue. 2 , 2014 , pp. 163-167 ; ISSN: 08943230 ; Fattahi, A ; Sharif University of Technology
Silica gel-confined ionic liquid (IL) is a class of heterogeneous catalysts with broad catalytic applications. Leaching of the IL from the surface of the support is the major drawback of these catalysts, which reduce the catalyst efficiency during the chemical reactions. To investigate the effect of the hydrogen bonding on the leaching phenomena, the interaction between the 1-ethyl-3-methylimidazolium-based IL with various anions (Cl-, Br-, HSO4 -, NO3 -, BF 4 -, and PF6 -) and the surface of the silica gel were studied using density functional theory. Hence, a hydroxylated cage-like cluster of silica gel, Si4O6(OH), was selected to mimic the surface. The values of ÎEinteraction show that...
Silver nanoparticles supported on silica-coated ferrite as magnetic and reusable catalysts for oxidant-free alcohol dehydrogenation, Article RSC Advances ; Volume 5, Issue 29 , Jan , 2015 , Pages 22503-22509 ; 20462069 (ISSN) ; Shakourian Fard, M ; Ehyaei, N ; Mahmoodi Hashemi, M ; Sharif University of Technology
Royal Society of Chemistry 2015
Silver (0) nanoparticles supported on silica-coated ferrite were synthesized to be used as an efficient and recyclable heterogeneous catalyst for oxidant-free dehydrogenation of alcohols to the corresponding carbonyl compounds. The catalyst can be easily recovered and reused for 8 reaction cycles without considerable loss of activity. The facile recovery of the catalyst is carried out by applying an external magnetic device. The catalyst was fully characterized by the techniques of TEM, SEM, XRD, EDS, ICP-AES, and VSM. This journal is