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    Evaluation of zeolites in production of tetrahydrofuran from 1,4-butanediol: Performance tests and kinetic investigations

    , Article Industrial and Engineering Chemistry Research ; Volume 46, Issue 3 , 2007 , Pages 726-733 ; 08885885 (ISSN) Aghaziarati, M ; Kazemeini, M ; Soltanieh, M ; Sahebdelfar, S ; Sharif University of Technology
    2007
    Abstract
    The liquid-phase dehydration of 1,4-butanediol to tetrahydrofuran was investigated over various materials including synthetic zeolites, namely, ZSM-5, Y, Mordenite, Ferrierite, and Beta as well as silica and alumina. The key characters investigated were the Si/Al ratio and cation exchange. The results showed that the ZSM-5 zeolite exchanged with NH4+ exhibited the highest activity in dehydration of 1,4-butanediol. In all tests, nearly 100% selectivity to tetrahydrofuran was observed. After finding the most active catalyst, the kinetics of dehydration of 1,4-butanediol to tetrahydrofuran was studied over this material. The influence of operating parameters such as temperature, pressure, and... 

    Kinetic study of heterogeneous catalytic hydrogenation of cyclohexene to cyclohexane in ionic liquid-alcohols mixtures

    , Article Applied Catalysis A: General ; Volume 341, Issue 1-2 , 2008 , Pages 58-64 ; 0926860X (ISSN) Khodadadi Moghaddam, M ; Habibi Yangjeh, A ; Gholami, M. R ; Sharif University of Technology
    2008
    Abstract
    Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/Al2O3, was carried out in solutions of 2-hydroxyethylammonium formate (a room temperature ionic liquid, RTIL) mixed with methanol, ethanol and propan-2-ol at 25 °C. The rate constants of the reaction in ionic liquid alcohol mixtures were higher than alcohol alone. First-order rate constant of the reaction in the RTIL relative to propan-2-ol is approximately 28. Furthermore, the rate constant of the reaction increases with the mole fraction of the ionic liquid. Single-parameter correlations of log k vs. normalized polarity parameter (ETN), hydrogen-bond acceptor basicity (β) and hydrogen-bond donor acidity (α) do not give... 

    Efficient oxidation of olefins and sulfides catalyzed by manganese(III)-tridentate Schiff base complex using UHP as oxidant

    , Article Catalysis Communications ; Volume 9, Issue 7 , 2008 , Pages 1600-1606 ; 15667367 (ISSN) Bagherzadeh, M ; Tahsini, L ; Latifi, R ; Sharif University of Technology
    2008
    Abstract
    Catalytic studies were performed to develop a simple oxidation system for olefins and sulfides using manganese(III)-tridentate Schiff base complex, Mn(N-OPh-sal)(acac)(EtOH) (N-HOPh-Hsal = N-hydroxyphenyl-salicyldienamine, Hacac = acetylacetone), and urea-hydrogen peroxide (UHP) as terminal oxidant. Conversions up to 90% for olefins at 0 °C and 96% for sulfides at room temperature as well as sulfoxide selectivity up to 73% were achieved in short reaction times. Also this study confirms the accelerating effect of strong π-donor axial ligands such as imidazole (ImH) on the oxidation reactions. © 2008 Elsevier B.V. All rights reserved  

    ZnO nanoparticles: An efficient nanocatalyst for the synthesis of β-acetamido ketones/esters via a multi-component reaction

    , Article Catalysis Communications ; Volume 9, Issue 2 , 2008 , Pages 299-306 ; 15667367 (ISSN) Mirjafary, Z ; Saeidian, H ; Sadeghi, A ; Matloubi Moghaddam, F ; Sharif University of Technology
    2008
    Abstract
    A convenient one-pot multi-component reaction of aromatic aldehydes, enolizable ketones or β-keto esters and acetonitrile in the presence of acetyl chloride and 10 mol% ZnO nanoparticles for the synthesis of β-acetamido ketones/esters at room temperature is described. © 2007 Elsevier B.V. All rights reserved  

    Application of thionine-nafion supported on multi-walled carbon nanotube for preparation of a modified electrode in simultaneous voltammetric detection of dopamine and ascorbic acid

    , Article Electrochimica Acta ; Volume 52, Issue 22 , 2007 , Pages 6310-6317 ; 00134686 (ISSN) Shahrokhian, S ; Zare Mehrjardi, H. R ; Sharif University of Technology
    2007
    Abstract
    A modified carbon-paste electrode (CPE) is prepared by incorporating thionine-nafion supported on multi-walled carbon nanotube (MWCNT). The electrochemical behavior of dopamine (DA) and ascorbic acid (AA) on the surface of the modified electrode is investigated by cyclic voltammetry (CV). The results show that thionine effectively immobilized in the matrix of the paste by using an appropriate mixture of nafion/MWCNT under the ultrasonic condition. On the other hand, presence of nafion enhances the stability of the thionine supported by MWCNT in the composite electrode and improves the reproducibility of the surface of the modified electrode under renewing process by polishing. The results of... 

    Catalytic activity of manganese(III)-oxazoline complexes in urea hydrogen peroxide epoxidation of olefins: The effect of axial ligands

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 260, Issue 1-2 , 2006 , Pages 163-169 ; 13811169 (ISSN) Bagherzadeh, M ; Latifi, R ; Tahsini, L ; Sharif University of Technology
    2006
    Abstract
    The catalytic activity of two manganese(III)-oxazoline complexes [Mn(phox)2(CH3OH)2]ClO4 and Mn(phox)3 (Hphox = 2-(2′-hydroxylphenyl)oxazoline), was studied in the epoxidation of various olefins. All of epoxidation reactions were carried out in (1:1) mixture of methanol:dichloromethane at room temperature using urea hydrogen peroxide (UHP) as oxidant and imidazole as co-catalyst. The epoxide yields clearly demonstrate the influence of steric and electronic properties of olefins, the catalysts and nitrogenous bases as axial ligand. [Mn(phox)2(CH3OH)2]ClO4 catalyst with low steric properties has higher catalytic activity than Mn(phox)3. The highest epoxide yield (95%) was achieved for indene... 

    An optimum catalyst for dehydration of 1, 4-butanediol in production of tetrahydrofuran

    , Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) Aghaziarati, M ; Kazemeini, M ; Soltanieh, M ; Sahebdelfar, S ; Sharif University of Technology
    2006
    Abstract
    In the present work, Tetrahydrofuran was produced from 1,4-butanediol by catalytically dehydration of 1,4-butanediol in contact with a catalyst. Material used as catalyst were Synthesized and natural zeolites as well as alumina and silica. Synthesized zeolites were investigated in different aspect such as pore size, cation and Si/Al ratio. Results indicated that with increasing the Si/Al ratio, the activity of the zeolite used for 1, 4-butanediol dehydration step was reduced. Furthermore, it was observed that, upon the replacement of sodium with hydrogen and ammonium cations, the conversion of the 1, 4-butanediol into tetrahydrofuran was increased. It was shown zeolites possessing smaller... 

    Electrocatalytic oxidation of methanol on a nickel electrode modified by nickel dimethylglyoxime complex in alkaline medium

    , Article Journal of Power Sources ; Volume 144, Issue 1 , 2005 , Pages 21-27 ; 03787753 (ISSN) Golikand, A. N ; Shahrokhian, S ; Asgari, M ; Ghannadi Maragheh, M ; Irannejad, L ; Khanchi, A ; Sharif University of Technology
    2005
    Abstract
    Electrocatalytic oxidation of methanol on a nickel disc electrode coated with nickel dimethyglyoxime complex (NiDMG), conditioned by potential recycling in a potential range of 100-700 mV (versus SCE) is studied by cyclic voltammetry in alkaline medium (0.10 M NaOH). The results show that the NiODMG layer formed at the surface of electrode behaves as an efficient electrocatalyst for the oxidation of methanol in alkaline medium via Ni(III) species with the cross exchange reaction occurring through out the layer at a low concentration of methanol. A plausible mechanism was proposed for catalytic oxidation of methanol at this modified electrode. Moreover, the effects of various parameters such... 

    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 Rafiaei, S. M ; Kim, A ; Shokouhimehr, M ; Sharif University of Technology
    Abstract
    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  

    Preparation and study of bi-supported Ziegler-Natta catalyst with nano graphene oxide and magnesium ethoxide supports for polymerization of polyethylene

    , Article Polymer Science - Series B ; Volume 58, Issue 3 , 2016 , Pages 271-277 ; 15600904 (ISSN) Kheradmand, A ; Ramazani SaadatAbadi, A ; Khorasheh, F ; Baghalha, M ; Bahrami, H ; Sharif University of Technology
    Maik Nauka-Interperiodica Publishing  2016
    Abstract
    In this study, we have reported the preparation of bi-supported Ziegler-Natta catalysts using magnesium ethoxide and graphene oxide as support. The polymerization process was carried out in slurry phase using triisobutylaluminum as a co-catalyst.The XRD analysis of TiCl4/graphene oxide/Mg(OEt)2 catalyst demonstrated that the space between the layers of graphene oxide had increased to 0.2 nm.The catalyst was characterized by XPS, BET, BJH, SEM, and TGA. The catalyst activity was studied for various Al/Ti molar ratios, and the catalyst activity was optimum at Al/Ti molar ratio of 315. © 2016, Pleiades Publishing, Ltd  

    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) Maleki, H ; Kazemeini, M ; Bastan, F ; Sharif University of Technology
    Abstract
    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) Moghaddam, F. M ; Eslami, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Abstract
    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... 

    Organocopper-based magnetically recoverable and reusable nanocatalyst for efficient synthesis of novel 1,2,3-triazole-based sulfonamides in green medium

    , Article Research on Chemical Intermediates ; Volume 44, Issue 1 , 2018 , Pages 601-612 ; 09226168 (ISSN) Saeidian, H ; Sadighian, H ; Arabgari, M ; Mirjafary, Z ; Ayati, S. E ; Najafi, E ; Matloubi Moghaddam, F ; Sharif University of Technology
    Springer Netherlands  2018
    Abstract
    Abstract: We report robust green synthesis of novel 1,2,3-triazole-based sulfonamides bearing different motifs such as fluorine under click conditions in presence of a copper-based magnetically recoverable and reusable heterogeneous nanocatalyst. The organocopper catalyst at 0.5 mol.% was highly recyclable (up to five times) when recovered using an external magnet without significant loss in catalytic activity. The mild reaction conditions and excellent yields (69–95 %) make this protocol an attractive method for efficient synthesis of the title compounds. The structure of product 3a was determined by Röntgen crystal structure analysis. Graphical Abstract: [Figure not available: see... 

    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) Bayat, A ; Shakourian Fard, M ; Talebloo, N ; Mahmoodi Hashemi, M ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Abstract
    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  

    Rosmarinus officinalis directed palladium nanoparticle synthesis: Investigation of potential anti-bacterial, anti-fungal and Mizoroki-Heck catalytic activities

    , Article Advanced Powder Technology ; Volume 31, Issue 4 , 2020 , Pages 1402-1411 Rabiee, N ; Bagherzadeh, M ; Kiani, M ; Ghadiri, A. M ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    The present work was aimed to account a green and eco-friendly synthesis of palladium nanoparticles using Rosmarinus officinalis leaves extracts for the first time, therefore, that can be an acceptable replacement for chemical media to improve potential biological properties. The synthesized palladium nanoparticles were fully characterized using FT-IR, XRD, FESEM, TEM and UV/Vis spectroscopy techniques. Catalytic activity was investigated by Mizoroki-Heck reaction, and optimized based on solvent, temperature and time of the reaction, and the best results were found in water as a green media without any additional reagents. Biological activity of the synthesized nanoparticles were evaluated... 

    Coke formation possibility during production of reducing gas in large scale direct reduction plant

    , Article Ironmaking and Steelmaking ; Volume 34, Issue 2 , 2007 , Pages 115-123 ; 03019233 (ISSN) Sadri, M ; Vakhshouri, K ; Hashemi, M. M. Y. M ; Sharif University of Technology
    2007
    Abstract
    For the production of synthesis gas utilised in Midrex direct reduction plants, catalytic steam/CO2 hydrocarbon reforming in tubular reformer is the major process. Owing to the high heat input through the Midrex reformer tube wall, the endothermic nature of reforming reactions, low mass velocity of feed gas and large tube diameter, the catalyst bed is exposed to considerable axial and radial temperature gradients. These radial concentration and temperature gradients may create local areas with potential for carbon formation. To investigate this phenomenon, a rigorous two-dimensional model is developed for simulating the operation of a Midrex reformer which applies a dual catalyst loading... 

    An experimental kinetic optimization of NDMA hydrogenation to UDMH and DMA on a Pd/C catalyst

    , Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) Gorji, M ; Kazememi, M ; Bozorgmehri, R ; Sharif University of Technology
    2006
    Abstract
    The Unsymmetrical dimethyl hydrazine (UDMH) apart from its use as a versatile rocket fuel, finds numerous industrial applications. Interest in UDMH for various applications in the missile and rocket industry has prompted the study of this member of hydrazine family to greater extent. It can be prepared in several ways but one of the most efficient ones which results in higher yields is the catalytic hydrogenation of Nitroso Dimethylamine (NDMA). In this work the kinetic of NDMA to UDMH hydrogenation on a 5% Pd/C in aqueous solution of NDMA was studied experimentally and optimum conditions of the reaction for maximum yield of UDMH in the presence of undesired dimethyl amine (DMA) product was... 

    Reactivity and characteristics of Pd/MOF and Pd/calcinated-MOF catalysts for CO oxidation reaction: Effect of oxygen and hydrogen

    , Article International Journal of Hydrogen Energy ; Volume 46, Issue 24 , 2021 , Pages 12822-12834 ; 03603199 (ISSN) Abbasi, F ; Karimi Sabet, J ; Ghotbi, C ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    For the first time, the effect of calcination process on characteristics and catalytic performances of Pd supported on different MOFs (MIL-101(Cr), NH2-MIL-101(Cr), and HKUST-1) was evaluated. Besides, the various orders of calcination process and reduction one on Pd/MOF and Pd/calcinated-MOF were studied, and their performances in CO oxidation reaction were presented to find the effect of H2 and O2. Results showed that the effect of calcination and reduction processes on the catalytic activities and characteristics strongly depends on the nature of MOF. Among MIL-based catalysts, the catalyst with no calcination treatment showed the best activity. Among MNH2-based catalysts, high activity... 

    Reactivity and characteristics of Pd/MOF and Pd/calcinated-MOF catalysts for CO oxidation reaction: Effect of oxygen and hydrogen

    , Article International Journal of Hydrogen Energy ; Volume 46, Issue 24 , 2021 , Pages 12822-12834 ; 03603199 (ISSN) Abbasi, F ; Karimi Sabet, J ; Ghotbi, C ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    For the first time, the effect of calcination process on characteristics and catalytic performances of Pd supported on different MOFs (MIL-101(Cr), NH2-MIL-101(Cr), and HKUST-1) was evaluated. Besides, the various orders of calcination process and reduction one on Pd/MOF and Pd/calcinated-MOF were studied, and their performances in CO oxidation reaction were presented to find the effect of H2 and O2. Results showed that the effect of calcination and reduction processes on the catalytic activities and characteristics strongly depends on the nature of MOF. Among MIL-based catalysts, the catalyst with no calcination treatment showed the best activity. Among MNH2-based catalysts, high activity... 

    Synthesis, characterization, electrochemical studies and catecholase-like activity of a series of mononuclear Cu(II), homodinuclear Cu(II)Cu(II) and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based compartmental ligand

    , Article Journal of Molecular Catalysis A: Chemical ; Volume 241, Issue 1-2 , 2005 , Pages 1-7 ; 13811169 (ISSN) Boghaei, D. M ; Behzad, M ; Bezaatpour, A ; Sharif University of Technology
    2005
    Abstract
    A series of previously reported mononuclear Cu(II) and homodinuclear Cu(II)Cu(II) complexes, as well as, novel mononuclear Cu(II), homodinuclear Cu(II)Cu(II), and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based dinucleating ligand with two different N(amine)2O2 and N(imine)2O2 coordination sites, were synthesized and characterized by elemental analyses, infrared and electronic absorption spectroscopies and conductivity measurements. The electrochemical behavior and catecholase-like activity of the complexes were also studied using cyclic voltammetry and UV-vis spectrophotometry, respectively. Our results show that the dinuclear complexes are more effective catalysts in the oxidation...