فهرست مطالب

communications in catalysis - Volume:1 Issue:2, 2018
  • Volume:1 Issue:2, 2018
  • تاریخ انتشار: 1397/09/02
  • تعداد عناوین: 6
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  • Shahab Khameneh asl *, Saeed Behjat Pages 1-12

    With increasing pollution and decrease in global reservoirs of fossil fuels, a lot of interest has been attracted to fuel cells as efficient and clean energy sources. Polymeric (membrane) fuel cells are special type of fuel cells, which can be built in small dimensions and power. These cells use hydrogen (and oxygen or air) and produce water. In these cells, platinum is used as electrode (and electro catalyst) both in anode and cathode, due to its low overvoltage for both hydrogen and oxygen. To increase the efficiency of these coatings, it is best to produce platinum particles with maximum area and it automatically leads to nanometric particles. In this thesis, platinum particles are electrodeposited first on Floride doped Tin Oxide (FTO) and then on graphite. Electro deposition is conducted via DC and pulse methods. Floride doped Tin Oxide (FTO) samples have been examined using voltametry in 0.5M H2SO4 and graphite samples have been examined in 0.5 M H2SO4 + 0.5 M CH3OH. Specific area of platinum on Floride doped Tin Oxide (FTO) substrates has been calculated. In graphite substrates, comparative analysis has been performed. Prepared samples have been examined using scanning electron microscope. For Floride doped Tin Oxide (FTO) sample, AFM test has been performed to approve the results of SEM. According to results, Platinum particles with approximate diameter of 30 nanometers have been successfully coated on Floride doped Tin Oxide (FTO) and graphite.

    Keywords: Nanometric coating, Pulse Electrodeposition, Pt-C, Polymeric, Fuel cells
  • Adeleh Moshtaghi Zonouz * Pages 13-20

    An efficient and simple synthesis of some 2-amino-3-cyano-4H-pyran derivatives was developed via the one-pot and three-component reaction of aldehydes, ethyl acetoacetate, and malononitrile in the presence of ammonium acetate at room temperature using catalytic amount of iodine. The key advantages of this method are the easy access to various substituted 2-amino-3-cyano-4H-pyran derivatives, short reaction times and high yields.

    Keywords: 2-Amino-3-cyano-4H-pyrans, One-pot reaction, Multi-component reaction, Molecular iodine, Synergistic effect
  • Abdolreza Abri *, Mostafa Ebrahilou Pages 21-31

    Coumarin and its derivatives are the most important components of several bioactive compounds such as anticoagulants, anti-HIVs, anti-tumors, anti-oxidants, anti-anxieties, anti-inflammatories, hypnotics, helminthicides, and insecticides. Derivatives of 2H-Chromen-2-one, or coumarins, are synthesized mainly through pechmann condensation reactions. This condensation involves phenol derivatives and β -ketoesters that occur in the presence of an acidic catalyst under reflux, but the yield of coumarin derivatives obtained in this method is very low and the reaction time is long. Although a lot of modified methods have been proposed, each one of them has some disadvantages, such as hard conditions, low efficiency, long time, expensive reagents, formation of byproducts, and difficulty of recycling and reusing the catalyst. In this research, an efficient method is offered for synthesis of some coumarin derivatives using pechmann condensation reactions in the presence of phenol and ethyl acetoacetate with sodium hydrogen sulfate stabilized on nanosilica as the catalyst. This method has advantages, such as high yields, short reaction time, simple purification.

    Keywords: Pechmann condensation, Sodium hydrogen sulfate, Nano silica, Coumarin, Sol-gel
  • Majid Saghi, Kazem Mahanpoor * Pages 32-53

    In the research, spherical α-Fe2O3 nanoparticles (NPs) were synthesized and supported on the surface of 12-tungstosilicic acid (12-TSA.7H2O) using forced hydrolysis and reflux condensation (FHRC) method. Photocatalytic activity of pure and supported α-Fe2O3 NPs (α-Fe2O3/2-TSA.7H2O) for Tetracycline (TC) and Doxycycline (DC) degradation was investigated using UV/H2O2 process. The products were characterized by FTIR, SEM/EDX, BET surface area and XRD. The experiments were designed considering four variables including pH, the initial concentration of pollutant, catalyst concentration and H2O2 concentration at two-levels and three central point's using full factorial experimental design. The results indicated that supporting α-Fe2O3 NPs caused to improve the filtration, recovery and photocatalytic activity of NPs.Under optimal conditions, 88.44% TC and 87.67% DC were degraded following 50 and 120 min, respectively. The results indicated that reactions follows first-order kinetic and rate coefficient for TC and DC degradation reactions equals to 0.0178 and 0.0074 min–1, respectively.

    Keywords: Tetracycline, Doxycycline, Full factorial, ?-Fe2O3, ?-Keggin
  • Mahdi Jafarnejad *, Farnoosh Panahi, Hossein Iloukhani, Khatereh Khanlarzadeh Pages 54-69

    The densities, ρ and refractive index, nD of mixtures consisting of 2-Propanol, 1, 3-Diaminopropane, and 2, 5-Dimethoxytetrahydrofuran have been measured at different temperatures. VEm, ṼEm,i, ΔnD , αE and (ǝHEm / ǝP )T,x for binary and VEm and ΔnD for ternary mixtures were derived. VEm and ΔnD for binary mixtures were correlated with the Redlich‒Kister equation and for ternary mixtures were correlated with several equations. Prediction geometrical solution models were used to predict VEm, ΔnD of ternary mixtures and standard deviation for their fitting was reported. Positive deviation from ideal state were recorded for VEm in mixture of 1, 3-Diaminopropane + 2, 5-Dimethoxytetrahydrofuran and 2-Propanol + 2, 5-Dimethoxytetra-hydrofuran mixtures. However in mixture of 2-Propanol and 1, 3-Diaminopropane negative deviation in the high composition of 1, 3-Diaminopropane varies to positive in the dominated mole fraction of alcohol which was analyzed to interpret the molecular interactions.

    Keywords: Ternary mixtures, Volumetric properties, Refractive index, Molecular interactions, Prediction models
  • Nabieh Farhami *, Majid Monajjemi, karim Zzare Pages 70-75

    In this work Nano capacitor was studied by carbon nanotubes electrodes and dielectric of nanotube Boron Nitride. In this research, there are four different configurations which consists of (3,3) & (6,6) & (13,13), (4,4) & (8,8) & (14,14), (5,5) & (10,10) & (15,15), (6,6) & (12,12) & (17,17) and also we calculated total charge electric, potential difference between electrodes, capacity and dielectric constant. All calculations are based on DFT theory and semi empirical method.

    Keywords: Boron Nitride nanotube, Capacitor, Carbon nanotube, Quantum mechanics, Computational chemistry