Loading...
Search for: ruthenium
0.006 seconds
Total 30 records

    Synthesis and Characterization of a novel Ruthenium(II) Complex With Bidentate O,N-donor OxazolineLigand and Study of Catalytic Oxidation of Sulfides and Alkanes

    , M.Sc. Thesis Sharif University of Technology Hosseini, Mojtaba (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    Abstract
    The 2-(2′-hydroxyphenyl)-oxazoline ligand (Hphox) is generated from 1:1 condensation of methyl salicylate with 2-aminoethanol. Novel [Ru(Hphox)2(H2O)2] (Hphox = 2-(2′-hydroxyphenyl)-oxazoline ) complex has been synthesized and characterized by physic-chemical methods. Oxidation of sulfides catalyzed by the mixed-ligand ruthenium(II) complex [Ru(Hphox)2(H2O)2]using urea-hydrogen peroxide (UHP) as oxidant was investigated under mild condition within 1 h. The results showed that mixed-ligand ruthenium(II) complex was effective catalyst in oxidation of sulfides in whichsulfoxideswere the only products. Using this catalytic system in the oxidation of alkanes, ketones were obtained as the main... 

    Minimizing CO2 formation in Ir-catalyzed methanol carbonylation process

    , Article 20th International Congress of Chemical and Process Engineering, CHISA 2012, Prague, 25 August 2012 through 29 August 2012 ; 2012 , Pages 1179-1188 ; 18777058 (ISSN) Kazemeini, M ; Hosseinpour, V ; Sharif University of Technology
    2012
    Abstract
    Acetic acid is one of the most important petrochemical products. Carbonylation of methanol in homogenous phase is one of the major routes for production of acetic acid. Amongst group VIII metal catalysts used in this process iridium has displayed the best capabilities. To investigate effect of operating parameters like: temperature, pressure, methyl iodide, methyl acetate, iridium, ruthenium, and water concentrations on the carbon dioxide formation, experimental design for this system based upon central composite design (CCD) was utilized. Statistical carbon dioxide formation equation developed by this method contained individual, interactions and curvature effects of parameters on the... 

    Intrinsically Ru-doped suboxide TiO2nanotubes for enhanced photoelectrocatalytic H2generation

    , Article Journal of Physical Chemistry C ; Volume 125, Issue 11 , 2021 , Pages 6116-6127 ; 19327447 (ISSN) Khorashadizade, E ; Mohajernia, S ; Hejazi, S ; Mehdipour, H ; Naseri, N ; Moradlou, O ; Moshfegh, A. Z ; Schmuki, P ; Sharif University of Technology
    American Chemical Society  2021
    Abstract
    In the present research, we investigate the synergistic effects of Ru-doping and Ar/H2 reduction treatment on the photoelectrochemical water splitting performance and hydrogen evolution rate of TiO2 nanotube array photoelectrodes. The Ti-Ru alloy with 0.2 at. % Ru was used to grow anodic self-organized Ru-doped TiO2 nanotube layers. An ideal synergy between Ar/H2 reduction treatment and Ru-doping results in the extended absorption toward the visible light region and improved photoelectrocatalytic activity. The black Ru-doped TiO2-x photoanode's water splitting rate improves remarkably (∼ninefold) compared to the black TiO2-x sample (∼twofold). Moreover, the black Ru-doped TiO2-x photoanode... 

    Synthesis and Study of Catalytic Activity of[Ru(oxazine)2(EtOH)2]Cl complex in epoxidation of Olefins and Oxidation of Alkanes, Alcohol and Sulfide with TBHP and UHP

    , M.Sc. Thesis Sharif University of Technology Gohari Derakhshande, Parviz (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    Abstract
    Ruthenium complexes with their wide range of stable but chemically accessible oxidation states have been extensively studied as catalyst of hydrocarbon oxidation. In recent years, these complexes with various ligands have been reported as new catalysts with better selectivity and several co-oxidations. Ruthenium complexes act as oxidation catalyst, often via ruthenium-oxo species as active intermediates in the oxygen transfer process, oxidizing alcohols or alkanes and epoxidizing alkane. Here, we reported the synthesis and catalytic activity of a ruthenium(III) complex with bidentate oxazine ligand. The new synthesized Ru(III)-oxazine complex was characterized by IR and UV-Vis spectra and... 

    Electrical and magnetic properties of RuGd1.6Ce 0.4Sr2Cu2O10-δ

    , Article 4th International Conference on Magnetic and Superconducting Materials, MSM'05, Agadir, 5 September 2006 through 8 September 2006 ; Volume 3, Issue 9 , 2006 , Pages 2964-2967 ; 18626351 (ISSN) Sabri, D ; Hadipour, H ; Mirzadeh, M ; Akhavan, M ; Sharif University of Technology
    2006
    Abstract
    We have studied the electrical and magnetic properties of normal and superconducting states of RuGd1.6Ce0.4Sr 2Cu2O10-δ (Ru-1222) system, prepared by the standard solid-state reaction technique, with applied magnetic field. The resistivity curves show that at high temperature the system is paramagnetic. At lower temperature, we can observe two magnetic transitions from paramagnetic state to anti-ferromagnetic and from anti-ferromagnetic to ferromagnetic. At room temperature the resistivity of sample shows insulating behavior and superconducting transition occurs at 45 K. Superconducting and magnetic parameters such as superconducting transition temperature Tc, magnetic transition Tirr, have... 

    Modification of Vertically Aligned Carbon Nanotubes with RuO2 for a Solid-State pH Sensor

    , M.Sc. Thesis Sharif University of Technology Kahram, Mohaddeseh (Author) ; Dolati, Abolghasem (Supervisor)
    Abstract
    In this work, a novel type electrode based on RuO2 nanoparticles-modified vertically aligned carbon nanotubes (RuO2/MWCNTs) was investigated. ThisRuO2/MWCNTs electrode not only shows a high capacity nature,but also possesses a good response to the pH value. In order to develope this sensor, aligned carbon nanotubes were synthesized by the chemical vapor deposition at first and then modified with RuO2 nanopartcles by sol-gel method. Various parameters affecting the growth of nanotubes, such as substrate type, surface finishing, surface roughness, the growth temperature and carbon feed rate was studiedand and optimal conditions for growth were obtained. At last, aligned nanotubes with a... 

    A mathematical model of nanoparticulate mixed oxide pseudocapacitors; Part II: The effects of intrinsic factors

    , Article Journal of Solid State Electrochemistry ; Volume 15, Issue 1 , 2011 , Pages 115-123 ; 14328488 (ISSN) Farsi, H ; Gobal, F ; Sharif University of Technology
    Abstract
    Our previously reported mathematical model for a mixed oxide nanoparticulate-based supercapacitor containing RuO2·xH2O and MO2·yH2O (M being another suitable transition metal) was analyzed. Both double-layer and faradaic processes responsible for charge/discharge were considered. The effects of the intrinsic factors, unit cell length, state of charge, and the exchange current densities of the electrochemical processes of the constituents on the performance of the model supercapacitor were clarified. Compensation effects where each constituent compensates the shortcomings of the other at specific conditions of discharge are analyzed in the light of the model  

    Non-covalent sulfoxide⋯(nitrosyl group) interactions involving coordinated nitrosyl in a Ru(ii) nitrosyl complex with an α-diimine ligand: Structural and computational studies

    , Article CrystEngComm ; Volume 22, Issue 44 , October , 2020 , Pages 7532-7537 Kia, R ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Abstract
    Investigation of the X-ray structure of the newly prepared [Ru(NO)(2,6isopPh2Aceq)Cl3] (2,6isopPh2Aceq = bis(2,6-diisopropylphenylimino)acenaphthenequinone) complex revealed for the first time the π-hole interaction involving the coordinated nitrosyl group with DMSO as the solvent of crystallization in the crystal lattice. Processing of CSD data showed only one reported structure. A significant feature of the structure is the presence of n → π∗, π → σ∗, and n → σ∗ interactions due to the coordinated nitrosyl and chloro groups and DMSO. © 2020 The Royal Society of Chemistry  

    Effect of Ce substitution in RuGd2-xCexSr 2Cu2O10-δ (Ru-1222)

    , Article 4th International Conference on Magnetic and Superconducting Materials, MSM'05, Agadir, 5 September 2006 through 8 September 2006 ; Volume 3, Issue 9 , 2006 , Pages 2982-2985 ; 18626351 (ISSN) Hadipour, H ; Sabri, D ; Mirzadeh, M ; Akhavan, M ; Sharif University of Technology
    2006
    Abstract
    We have studied the electrical and magnetic properties of RuGd 2-xCexSr2Cu2O10-δ (Ru-1222) with content of Ce = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, prepared by the standard solid-state reaction technique. To determine how the magnetic and superconducting properties of this layered cuprate system can be affected by Ce substitution, the resistivity and magnetoresistivity have been measured at various temperatures. Resistivity curves reveal the presence of four regions for various contents of x. In high temperatures, system is paramagnetic. Magnetic transition from paramagnetic state to antiferromagnetic state occurs at 140 K for x = 0, which varies very slowly with increasing Ce substitution for Gd.... 

    Synthesis and electrochemical characterization of sol-gel-derived RuO 2/carbon nanotube composites

    , Article Journal of Solid State Electrochemistry ; Vol. 18, Issue 4 , April , 2014 , pp. 993-1003 ; Online ISSN: 1433-0768 Kahram, M ; Asnavandi, M ; Dolati, A ; Sharif University of Technology
    Abstract
    Ruthenium oxide was coated on multiwalled carbon nanotubes (MWCNTs) to obtain nanocomposite electrode which has a good response to the pH. To synthesize this electrode, gold and cobalt were coated on a stainless steel 304 substrates, respectively, and then, vertically aligned carbon nanotubes were grown on the prepared substrates by chemical vapor deposition. Gold reduced activity of the stainless steel, while cobalt served as a catalyst for growth of the carbon nanotube. Ruthenium oxide was then coated on MWCNTs via sol-gel method. At last, different techniques were used to characterize the properties of synthesized electrode including scanning electron microscopy (SEM), transmission... 

    Effect of Ca substitution on crystal structure and superconducting properties of ferromagnetic superconductor RuSr 2-xCa xGd 1.4Ce 0.6Cu 2O 10 -δ

    , Article Journal of Magnetism and Magnetic Materials ; Volume 324, Issue 6 , 2012 , Pages 949-954 ; 03048853 (ISSN) Fallahi, S ; Mazaheri, M ; Nikseresht, N ; Rønnow, H. M ; Akhavan, M ; Sharif University of Technology
    2012
    Abstract
    We have investigated the effect of Ca substitution for Sr site on structural, magnetic and superconducting properties of RuSr2 -x CaxGd1.4Ce0.6Cu2O10 -δ system. In this system, the magnetic coupling of RuO 2 and CuO 2 plays an important role in magnetic and superconducting states. X-ray diffraction analysis shows that all samples are single phase and the lattice parameters decrease continuously by increasing Ca content. The onset superconducting transition temperature is found to decrease with Ca substitution. As Ca content increases, rotation of the RuO 6 octahedron increases and RuO(1)Ru angle decreases. These variations strengthen the magnetic moments in the RuO 2 planes. The enhancement... 

    An experimental design approach to determine effects of the operating parameters on the rate of Ru promoted Ir carbonylation of methanol

    , Article World Academy of Science, Engineering and Technology ; Volume 73 , March , 2011 , Pages 598-603 ; 2010376X (ISSN) Hosseinpour, V ; Kazemini, M ; Mohammadrezaee, A ; Sharif University of Technology
    Abstract
    carbonylation of methanol in homogenous phase is one of the major routesfor production of acetic acid. Amongst group VIII metal catalysts used in this process iridium has displayed the best capabilities. To investigate effect of operating parameters like: temperature, pressure, methyl iodide, methyl acetate, iridium, ruthenium, and water concentrations on the reaction rate, experimental design for this system based upon central composite design (CCD) was utilized. Statistical rate equation developed by this method contained individual, interactions and curvature effects of parameters on the reaction rate. The model with p-value less than 0.0001 and R 2 values greater than 0.9; confirmeda... 

    Optimisation of Ru-promoted Ir-catalysed methanol carbonylation utilising response surface methodology

    , Article Applied Catalysis A: General ; Volume 394, Issue 1-2 , February , 2011 , Pages 166-175 ; 0926860X (ISSN) Hosseinpour, V ; Kazemeini, M ; Mohammadrezaee, A ; Sharif University of Technology
    2011
    Abstract
    In this study, central composite design (CCD) at five levels (-1.63, -1, 0, +1, +1.63) combined with response surface methodology (RSM) have been applied to optimise methanol carbonylation using a ruthenium-promoted iridium catalyst in a homogenous phase. The effect of seven process variables, including temperature, pressure, iridium, ruthenium, methyl iodide, methyl acetate and water concentrations, as well as their binary interactions, were modelled. The determined R 2 values greater than 0.9 for the rate and methane formation data confirmed that the quadratic equation properly fitted the obtained experimental data. The optimum conditions for maximum rate and minimum methane formation were... 

    Electrodeposition of Pt-Ru nanoparticles on multi-walled carbon nanotubes: Application in sensitive voltammetric determination of methyldopa

    , Article Electrochimica Acta ; Volume 58, Issue 1 , 2011 , Pages 125-133 ; 00134686 (ISSN) Shahrokhian, S ; Rastgar, S ; Sharif University of Technology
    2011
    Abstract
    A modified glassy carbon electrode, prepared by potentiostatic electrodeposition of platinum-ruthenium nanoparticles (Pt-RuNPs) onto a multi-walled carbon nanotube (MWCNT) layer, offers dramatic improvements in the stability and sensitivity of voltammetric responses toward methyldopa (m-dopa) compared to glassy carbon electrodes individually coated with MWCNT or Pt-RuNPs. The surface morphology and nature of the hybrid film (Pt-RuNPs/MWCNT) deposited on glassy carbon electrodes was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. A remarkable enhancement in the microscopic area of the electrode together... 

    Electrochemical Behaviors of RuO2-TiO2 Mixed Metal Oxide Coated on Titanium Anodes in Chlor-Alkali Electrolysis

    , M.Sc. Thesis Sharif University of Technology Paryani, Kasra (Author) ; Ghorbani, Mohammad (Supervisor)
    Abstract
    Titanium anodes activated by noble metal oxides under the trade name of dimensionally stable anodes (DSAs) are widely used in the electrolytic industry, particularly in chlor – alkali electrolysis. Over 20 years of use, the fundamental aspects of their long – lasting performance are not fully understand and the corrosion mechanisms are still the subject of many investigations. RuO2 – TiO2 coatings on titanium substrate, due to proper electrochemical characteristics and good corrosion resistance, is most applicable as an anode in chlor – alkali systems. In the present investigation, the first layer of Pt – Ir coating is applied via electrodeposition method on the pretreated titanium substrate... 

    Kinetic Study of Carbonylation of Methanol Using Homogenous Iridium Catalyst

    , M.Sc. Thesis Sharif University of Technology Hosseinpour, Vahid (Author) ; Kazemeini, Mohammad (Supervisor) ; Mhammad Rezaee, Alireza (Supervisor)
    Abstract
    Homogenous carbonylation of methanol is a major way to acetic acid. In this study central composite design (CCD) at five level (-1.63, -1, 0, +1, +1.63) combined with response surface methodology (RSM) have been applied to optimize carbonylation of methanol using ruthenium promoted iridium catalyst in homogenous phase. The effect of seven process variables including; temperature, pressure, iridium, ruthenium, methyl iodide, methyl acetate and water concentrations as well as, their interactions were modeled. The determined R2 values greater than 0.9 for the rate, methane, carbon dioxide and hydrogen formation data, confirmed quadratic equation properly fitted obtained experimental data. The... 

    Predictive construction of phase diagram of ternary solutions containing polymer/solvent/nonsolvent using modified Flory-Huggins model

    , Article Journal of Molecular Liquids ; Volume 263 , 2018 , Pages 282-287 ; 01677322 (ISSN) Sadeghi, A ; Nazem, H ; Rezakazemi, M ; Shirazian, S ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    The Flory-Huggins (FH) model has been one of the most used models in theoretical calculations which has been proved to be sensitive to values assigned as interaction parameters. In this work, a predictive equation is implemented to implicitly couple the concept of compressible regular solution theory of Ruzette and Mayes into the original FH model to obtain a new concertation-dependent interaction parameter equation. Then, the modified model (m-FH) is applied for construction of phase diagram of ternary solutions containing polymer/solvent/nonsolvent where experimental data for ternary systems were collected from the literature. In order to compare and analyze the model performance, the... 

    Urchin-like hierarchical ruthenium cobalt oxide nanosheets on Ti3C2T: XMXene as a binder-free bifunctional electrode for overall water splitting and supercapacitors

    , Article Nanoscale ; Volume 14, Issue 4 , 2022 , Pages 1347-1362 ; 20403364 (ISSN) Asen, P ; Esfandiar, A ; Mehdipour, H ; Sharif University of Technology
    Royal Society of Chemistry  2022
    Abstract
    Synthesizing efficient electrode materials for water splitting and supercapacitors is essential for developing clean electrochemical energy conversion/storage devices. In the present work, we report the construction of a ruthenium cobalt oxide (RuCo2O4)/Ti3C2Tx MXene hybrid by electrophoretic deposition of Ti3C2Tx MXene on nickel foam (NF) followed by RuCo2O4 nanostructure growth through an electrodeposition process. Owing to the strong interactions between RuCo2O4 and Ti3C2Tx sheets, which are verified by density functional theory (DFT)-based simulations, RuCo2O4/Ti3C2Tx MXene@NF can serve as a bifunctional electrode for both water splitting and supercapacitor applications. This electrode... 

    Mesoporous nanostructures of NiCo-LDH/ZnCo2O4 as an efficient electrocatalyst for oxygen evolution reaction

    , Article Journal of Colloid and Interface Science ; Volume 604 , 2021 , Pages 832-843 ; 00219797 (ISSN) Shamloofard, M ; Shahrokhian, S ; Amini, M. K ; Sharif University of Technology
    Academic Press Inc  2021
    Abstract
    Increasing energy demands for pollution-free and renewable energy technologies have stimulated intense research on the development of inexpensive, highly efficient, and stable non-noble metal electrocatalysts for oxygen evolution reaction (OER). In this study, a superior OER performance was achieved using a tri-metallic (Zn, Co, Ni) high-performance electrocatalyst. We successfully fabricated a peony-flower-like hierarchical ZnCo2O4 through an additive-free hydrothermal reaction followed by heat treatment. Then NiCo-LDH (layered double hydroxides) nano-flakes was electrodeposited on the ZnCo2O4/GCE surface to prepare NiCo-LDH/ZnCo2O4/GCE which was used as electrode for OER. The structure and... 

    Ruthenium/Ruthenium oxide hybrid nanoparticles anchored on hollow spherical Copper-Cobalt Nitride/Nitrogen doped carbon nanostructures to promote alkaline water splitting: Boosting catalytic performance via synergy between morphology engineering, electron transfer tuning and electronic behavior modulation

    , Article Journal of Colloid and Interface Science ; Volume 626 , 2022 , Pages 1070-1084 ; 00219797 (ISSN) Rezaee, S ; Shahrokhian, S ; Sharif University of Technology
    Academic Press Inc  2022
    Abstract
    Exploring bi-functional electrocatalysts with excellent activity, good durability, and cost-effectiveness for electrochemical hydrogen and oxygen evolution reactions (HER and OER) in the same electrolyte is a critical step towards a sustainable hydrogen economy. Three main features such as high density of active sites, improved charge transfer, and optimized electronic configuration have positive effects on the electrocatalyst activity. In this context, understanding structure–composition–property relationships and catalyst activity is very important and highly desirable. Herein, for the first time, we present the design and fabrication of novel MOF-derived ultra-small Ru/RuO2 nanoparticles...