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    Modeling Catalyst Deactivation in Catalytic Wet Air Oxidation of Phenol in Fixed Bed Three-Phase Reactors

    , M.Sc. Thesis Sharif University of Technology Golestani, Akram (Author) ; Kazemeini, Mohammad (Supervisor) ; Khorasheh, Farhad (Supervisor)
    In the present work, wet air oxidation of phenol over 7/3 MnO2/CeO2 composite oxide catalyst in trickle-bed and packed-bubble column reactors was modeled. Complexity of wet air oxidation reactions and catalyst poisoning with carbonaceous groups, on the surface and in the pores of catalyst, make the modeling process complicated. Plurality of mass balance equations which are confirmed in the catalyst pellet and in dynamic and static bed phase, also the equation of catalyst deactivation, lead us solve them simultaneously. In addition, the equations are two dimension and unsteady state and carbon of oxidation intermediates are present which make the modeling process more complicated. We are... 

    Synthesis and Characterization of Transition Metal Complexes with Carboxamide Ligands and Nanostructures for Catalytic and Antibacterial Activites Application

    , Ph.D. Dissertation Sharif University of Technology Kiani, Mahsa (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    Carboxamide ligands have been part of the growing research in the field of coordination chemistry of transition metal complexes. The solvent used in the classical method of synthesis of these compounds is pyridine, a solvent which is extremely toxic. In this project, we have developed a new method of synthesis using ionic liquids as the reaction media and have prepared Hqcq (1), Htp(2) under optimum conditions for Pd(II) and Pt(II) complexes of Hqcq and Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes of Htp with the formula:[Pd(qcq)(OAc)] (1a), [Pt(qcq)(Cl)] (1b), [Co(Htp)2(H2O)2].C2H5OH (2a), Co3O4 (2b), [Cu(tp)2(H2O)].CHCl3 (2c), CuO (2d), [Zn(tp)2(H2O)2] (2e), [Cd(tp)2(H2O)2].CH3OH... 

    Study of Catalytic Activity of Zirconium-Based Metal-Organic Frameworks in the Epoxide Ring-Opening Reactions

    , M.Sc. Thesis Sharif University of Technology Chegeni, Mohsen (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In current research, two zirconium-based metal-organic frameworks, MIP-202 (Zr) and UIO-66(CO2H)2 were employed as catalysts in the epoxy ring-opening reactions by amino and alcoholic nucleophiles. Firstly, these metal-organic frameworks were prepared under mild synthetic conditions and then characterized by means of spectral techniques such as X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FT-IR), electron microscopy Scanning (SEM) and X-ray energy diffraction (EDAX) spectroscopy were confirmed. Finally, their catalytic activity in epoxy ring-opening reactions was investigated and in to determine optimal conditions, the... 

    Examination of Activity of Three-Way Catalysts Toward CO and Hydrocarbon Emission Reduction from Tehran Gasoline Taxis

    , M.Sc. Thesis Sharif University of Technology Nasibi, Arman (Author) ; Hamzehlouyan, Tayebeh (Supervisor) ; Hosseini, Vahid (Co-Supervisor)
    Air pollution is one of the main environmental problems in Iran's metropolises, especially in the city of Tehran. Taxis have a significant contribution to pollution due to the long distances they travel during the day. Due to the fact that the operation of automotive three-way catalysts is a function of their operating conditions, and considering the different fuel composition in Iran and the specific conditions of engine performance, exhaust gas composition can be different from similar cases abroad. A commercial three-way catalyst was tested to evaluate its performance under conditions relevant to the exhaust gas of Tehran's taxis fleet. In this study, CO and C3H6 were considered as the... 

    Design and Synthesis of Heterogeneous Nanocatalysts Based on Immobilized Metals on Polymeric Substrates and their Applications in Organic Reactions

    , Ph.D. Dissertation Sharif University of Technology Motamedi, Anahita (Author) ; Pourjavadi, Ali (Supervisor)
    Today, catalysts have shown the growing applications in chemical industries especially for drug synthesis. Using immobilized heterogeneous catalysts is a sensible way to benefit from advantages of both heterogeneous and homogeneous catalysts. In this regards, homogeneous catalysts are immobilized on to a solid support through various methods. However, low loading amount of homogenous part and subsequently insufficient catalytic activity are main limitations of immobilized heterogeneous catalysts. For this reason, polymeric supports have been introduced to immobilize metal ions or nanoparticles. These polymeric supports not only possess advantages such as anti-corrosive properties, simple... 

    Examination of Activity of Oxidation Catalysts Toward Co and Hydrocarbon Emission Reduction from 4-Stroke Gasoline Carburetor Scooters in Tehran

    , M.Sc. Thesis Sharif University of Technology Lotfollahzadeh Moghaddam, Alireza (Author) ; Hamzehlouyan, Tayebeh (Supervisor) ; Hosseini, Vahid (Co-Supervisor)
    Over one million motorcycles operating in Tehran produce significant amounts of CO and unburnt hydrocarbons, thereby considered as one of the major contributors to air pollution in the city of Tehran. Oxidation catalysts, as emission control device, can reduce CO and hydrocarbon emissions from motorcycles. The efficiency of these catalysts under typical operating conditions of vehicles exhaust gas has been studied in the literature. However, due to the specific features of motorcycles exhaust gas in Tehran, such as low air to fuel ratio, different exhaust gas composition and significant amount of lubricating oil consumption, selection of a highly active, durable and cost-effective catalyst... 

    Synthesis of Modified Porous Nanostructures and Investigation of Oxidation Reaction Kinetics

    , M.Sc. Thesis Sharif University of Technology Gholizadeh, Sepideh (Author) ; Gholami, Mohammad Reza (Supervisor)
    In this work ،we used the hydrothermal method for prepared the Bivo4 nano particles. For the best photocatality property these nano particles stabilized on the different basis. This catalysis characterized by UV-vis, XRD, BET, FTIR and SEM. The size of zeolites catalyst were 22 nm and size of Bivo4 were 54 nm and the SEM showed that the BivO4 were sphere. By addition of BiVO4 nano particles to the surface of zeolite, the surface area was increase, but addition of BiVO4 nano particles to surface, the average of holes size decreased and distribution of holes will be monotonous and the surface area increased. In the continue for investigation of photo catalyst activity of nano particle, we used... 

    Preparation of Metal Nanoparticles/Ionic Liquid Composites and Investigation of Their Catalytic Activity

    , M.Sc. Thesis Sharif University of Technology Gharegozloo, Nazanin (Author) ; Gholami, Mohammad Reza (Supervisor) ; Salari, Hadi (Co-Advisor)
    In this research Fe3O4 magnetic nanoparticles were prepared. To protect against oxidation, a shell of SiO2 was deposited on Fe3O4. Graphene oxide was prepared by the modified Hummer method and supported on the Fe3O4@SiO2 core-shell. Then, ionic liquid layer was impregnated on it. Afterward, PtAu nano alloy were synthesized on the surface of nanocomposite with the different molar ration including 100:0, 75:25, 50:50, 25:75 and 0:100. The as-prepared nanocomposite was characterized by SEM, XRD, and FT-IR analytical methods.For investigation of kinetically activity of catalysts, reduction of 4-nitrophenol with NaBH4 as reducer was used. The adsorption in different times was obtained by UV-vis... 

    Thesis Title Synthesis and Characterization of Metal Nano Oxids and Investigation of their Catalytic Activity

    , M.Sc. Thesis Sharif University of Technology Falamarzi Askarani, Mehrdad (Author) ; Gholami, Mohammad Reza (Supervisor)
    In this project, the catalytic properties of CuO and ZnO were investigated in reduction reactions.MOFs were used as a precursor to preparation of these metal oxides. Gold and silver nanoparticles were used to improve the catalytic properties of the prepared metal oxides. Structural characteristics of nanocatalysts were stydied by SEM, TEM, XRD and FT-IR techniques. The prepared nanocomposites were applied in the catalytic reduction of paranitrophenol in the presence of sodium borohydride and the kinetics and mechanism were investigated according to the structure of the prepared catalysts  

    Synthesis and Characterization of Bis[2-(2׳-Hydroxyphenyl)- -oxazolinato]Ni(II) Complex and Investigation of it׳s Catalytic Activity in C-C Coupling Heck Reaction

    , M.Sc. Thesis Sharif University of Technology Arab, Zeynab (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In this study a new Ni(II)-¬oxazoline complex was synthesized by reaction of Ni(CH3COO)2.4H2O and 2-(2׳-hydroxyphenyl)-2-oxazoline ligand in MeOH solvent. The resulting complex bis[2-(2׳-hydroxyphenyl)-2-oxazolinato]Ni(II), was characterized by different spectroscopic methods. X-ray diffraction showed that this complex is four coordinated with a square planner geometry. The complex was applied as an efficient homogeneous catalyst in C-C coupling Heck reaction of arylhalides with olefins such as methylacrylate. Investigation of the catalytic activity of the complex in Heck reaction between arylhalides and olefins showed high yield and selectivity. For example reaction between iodobenzene and... 

    Experimental Study of the Aging Effect on the Oxidation Catalyst Performance as an Emission Control Device for 4-stroke Gasoline Carburetor Motorcycles

    , M.Sc. Thesis Sharif University of Technology Taheri, Arman (Author) ; Hamzehlouyan, Tayebeh (Supervisor)
    There are more than one million motorcycles in the city of Tehran that are responsible for significant amounts of various air pollutants emissions such as carbon monoxide and hydrocarbons. Oxidation catalysis, as the exhaust aftertreatment system of motorcycles, can reduce the emission of CO and hydrocarbon pollutants. The efficiency of these catalysts under typical operating conditions of vehicle exhaust gas has been studied in the literature. However, due to the specific features of motorcycles exhaust gas in Tehran, such as ultra-rich combustion, low air to fuel ratio (lambdas as low as 0.6-0.7), different exhaust gas composition and significant amount of lubricating oil consumption,... 

    Microwave-Assisted Coke Resistance and Mesoporous Ni-Co Catalyst in two Steps for Methane Steam Reforming

    , M.Sc. Thesis Sharif University of Technology Etminan, Azita (Author) ; Sadrnezhad, Khatiboleslam (Supervisor)
    Methane steam reforming (MSR) is an assuring reaction using steam to produce H2 as clean energy over a nickel-based catalyst. We synthesized monometallic NiMgAl2O4 and bimetallic NiCoMgAl2O4 catalysts in a two-step combustion method using urea, glycine, and sucrose, as fuel. BET-BJH, XRD, TGA, TPR, FESEM, and EDX-mapping characterized surface area, porosity, morphology, crystalline structure, and metal-support interaction behavior. The products exhibited well-structured, simple MgAl2O4 spinel and NiO without NiAl2O4, in both specimens. The MSR evaluation tests at 750℃ under atmospheric pressure, CH4: H2O feed ratio of 1:1.6 showed the bimetallic catalyst has the highest conversion (99.30%)... 

    Synthesis and Characterization of Tungsten (VI)Complex with Oxazine Ligand and its Catalytic Application in Oxidation of Sulfides to Sulfoxides

    , M.Sc. Thesis Sharif University of Technology Esmailpour Firoozsalary, Parvin (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In this study a novel oxo-diperoxo tungsten(VI) complex [WO(O2)2(phox)] was prepared by reaction of WO3 in H2O2 with oxazine-type ligand, 2-(2′-hydroxyphenyl)-5,6-dihydro-1,3-oxazine (Hphox). The complex was characterized by FTIR, 1H NMR and elemental analysis. The single-crystal X-ray diffraction studies revealed a seven coordinate tungsten center with a distorted octahedral geometry. The [WO(O2)2(phox)] complex was applied as a catalyst in efficient, and selective oxidation of sulfide to sulfoxide using 30% H2O2 or UHP as oxidants. This catalyst showed excellent catalytic activities and high selectivities in producing a variety of aryl and alkyl sulfoxides under mild conditions. To get... 

    Nanoparticle catalysts

    , Article Journal of Physics D: Applied Physics ; Volume 42, Issue 23 , 2009 ; 00223727 (ISSN) Zaker Moshfegh, A. R ; Sharif University of Technology
    In this review, the importance of nanoparticles (NPs), with emphasis on their general and specific properties, especially the high surface-to-volume ratio (A/V), in many technological and industrial applications is studied. Some physical and chemical preparation methods for growing several metallic and binary alloy NP catalysts are reviewed. The growth and mechanism of catalytic reactions for synthesis of 1D nanostructures such as ZnO nanowires and multiwall carbon nanotubes (MWCNTs) are discussed. Gas-phase production with emphasis on dependence of catalytic activity and selectivity on size, shape and structure of NPs is also investigated. Application of NP catalysts in several... 

    Silver nanoparticles modified carbon nanotube paste electrode for simultaneous determination of dopamine and ascorbic acid

    , Article Journal of Electroanalytical Chemistry ; Volume 633, Issue 1 , 2009 , Pages 85-91 ; 15726657 (ISSN) Tashkhourian, J ; Hormozi Nezhad, M. R ; Khodavesi, J ; Javadi, S ; Sharif University of Technology
    Elsevier  2009
    A novel modified carbon-paste electrode was employed for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) with good selectivity and high sensitivity. Silver nanoparticle and carbon nanotube modified carbon-paste electrode (Ag/CNT-CPE) displayed excellent electrochemical catalytic activities towards dopamine (DA) and ascorbic acid (AA). The oxidation overpotentials of DA and AA were decreased significantly compared with those obtained at the bare CPE. Differential pulse voltammetry was used for the simultaneous determination of DA and AA. The peak separation between DA and AA was 67 mV. The calibration curves for DA and AA were obtained in the range of 8.0 × 10-7-6.4 ×... 

    Application of pyrolytic graphite modified with nano-diamond/graphite film for simultaneous voltammetric determination of epinephrine and uric acid in the presence of ascorbic acid

    , Article Electrochimica Acta ; Volume 55, Issue 28 , 2010 , Pages 9090-9096 ; 00134686 (ISSN) Shahrokhian, S ; Khafaji, M ; Sharif University of Technology
    A novel modified pyrolytic graphite electrode with nano-diamond/graphite was fabricated. The electrochemical response characteristics of the modified electrode toward the epinephrine (EN) and uric acid (UA) were studied by means of cyclic and linear sweep voltammetry. The structural morphology and thickness of the film was characterized by SEM technique. The prepared electrode showed an excellent catalytic activity in the electrochemical oxidation of EN and UA, leading to remarkable enhancements in the corresponding peak currents and lowering the peak potentials. The prepared modified electrode acts as a highly sensitive sensor for simultaneous determination of EN and UA in the presence of... 

    Application of carbon-paste electrode modified with iron phthalocyanine for voltammetric determination of epinephrine in the presence of ascorbic acid and uric acid

    , Article Sensors and Actuators, B: Chemical ; Volume 137, Issue 2 , 2009 , Pages 669-675 ; 09254005 (ISSN) Shahrokhian, S ; Ghalkhani, M ; Amini, M. K ; Sharif University of Technology
    A carbon-paste electrode (CPE) modified with iron(II) phthalocyanine was used for the sensitive voltammetric determination of epinephrine (EN). The electrochemical response characteristics of the modified electrode toward EN, ascorbic acid (AA) and uric acid (UA) were investigated by cyclic and differential pulse voltammetry (CV and DPV). The results show an efficient catalytic activity of the electrode for the electro-oxidation of EN, which leads to improvement of reversibility of the electrode response and lowering its overpotential by more than 100 mV. The effect of pH and potential sweep rate on the mechanism of the electrode process was investigated. The modified electrode exhibits an... 

    Multi-walled carbon nanotubes with immobilised cobalt nanoparticle for modification of glassy carbon electrode: Application to sensitive voltammetric determination of thioridazine

    , Article Biosensors and Bioelectronics ; Volume 24, Issue 11 , 2009 , Pages 3235-3241 ; 09565663 (ISSN) Shahrokhian, S ; Ghalkhani, M ; Adeli, M ; Amini, M. K ; Sharif University of Technology
    Multi-walled carbon nanotubes (MWCNTs) were immobilised with cobalt nanoparticles and analyzed by transmission electron microscopy. This modification procedure substantially improved colloidal dispersion of the immobilised MWCNTs in water and organic solvents, yielding uniform and stable thin films for modification of the glassy carbon electrode surface. The modified electrode showed an efficient catalytic role for the electrochemical oxidation of thioridazine (TR), leading to remarkable decrease in its oxidation overpotential of approximately 100 mV and enhancement of the kinetics of the electrode reaction, which can be confirmed by increasing in the peak current and sharpness of the peak.... 

    Electrochemical study of Azathioprine at thin carbon nanoparticle composite film electrode

    , Article Electrochemistry Communications ; Volume 11, Issue 7 , 2009 , Pages 1425-1428 ; 13882481 (ISSN) Shahrokhian, S ; Ghalkhani, M ; Sharif University of Technology
    Thin carbon nanoparticle/Nafion film (CNP/N), as a novel electrode material, is formed on the surface of the glassy carbon electrode in a simple solvent evaporation process. The electrochemical behavior of Azathioprine (Aza) at the CNP/N-modified electrode is investigated in detail by the means of cyclic voltammetry. During the electrochemical reduction of Aza, an irreversible cathodic peak is appeared. Cyclic voltammetric studies indicated that the reduction process has an irreversible and adsorption-like behavior. The observed reduction peak is attributed to a four-electron process referring to the reduction of nitro group to the corresponding hydroxylamine. The prepared electrode showed... 

    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
    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...