فهرست مطالب

Iranian Journal of Catalysis
Volume:9 Issue: 1, winter 2019

  • تاریخ انتشار: 1397/12/10
  • تعداد عناوین: 10
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  • Kien Cuong Dao, Alexander Aleksandrovich Il’In, Ruslan Nikolaevich Rumyantsev *, Ulyana Sergeevna Uzhevskaya, Alexander Papvlovich Il’In, Taisiya Andreevna Rumyantseva Pages 1-9
    The interaction in the system of SnO2 and h-MoO3 prepared by their joint mechanical activation in a roller-ring vibratory mill was investigated. A series of catalysts was prepared with SnO2: h-MoO3 molar ratio 1:1; 1:2.3; 2.3:1 and 5.7:1. The catalysts were characterized by various techniques including X-ray phase, X-ray diffraction (XRD) and synchronous thermal analysis, scanning electron microscopy (SEM), BET method. An important effect of the introduction of molybdenum atoms into the structure of SnO2 was lattice defect. Heat treatment of the mechanically activated mixture at a temperature of 600–750  resulted in obtaining crystalline Sn(MoO4)2. The catalytic activity of the samples was investigated by the oxidative dehydrogenation of methanol. The results reported that varying the SnO2:MoO3 ratio allows adjusting the selectivity of the methanol conversion process over methyl formate and dimethyl ether.
    Keywords: Solid solution, SnO2, h-MoO3, Sn(MoO4)2, Mechanical activation, Catalytic properties
  • Bi Bi Fatemeh Mirjalili *, Reza Araqi, Seyed Ahmad Mohajeri Pages 11-19
    In this work, an efficient and green procedure for the synthesis of dihydro-2-oxypyrroles has been developed. One-pot four-component condensation reaction of aniline derivatives (2 mmol), dialkyl acetylene dicarboxylate (1 mmol), and aldehydes ( 1 mmol) was done in ethanol at 65 °C in the presence of nano-Fe3O4@SiO2/SnCl4 as a magnetically reusable heterogeneous acid catalyst. The obtained dihydro-2-oxypyrroles were purified without any chromatography techniques. The structure of obtained pure products was identified by physical properties and spectroscopic data such as FT-IR, 1H NMR, 13C NMR and mass spectroscopy. This protocol consistently has the advantages of excellent yields, short reaction time, simple workup, recyclability of the catalyst up to six runs without appreciable loss of activity.
    Keywords: Dihydro-2-oxypyrroles, Fe3O4@SiO2, SnCl4, Heterogeneous acid catalyst, Magnetic catalyst, Dialkyl acetylene dicarboxylate
  • Masoud Mokhtary * Pages 21-26
    Unripe grape juice (verjuice) as a natural catalyst was successfully applied to perform the one-pot reaction of aryl aldehydes, malononitrile, hydrazine hydrate and ethyl acetoacetate to synthesize pyranopyrazole derivatives in aqueous ethanol at room temperature in excellent yields. Furthermore, unripe grape juice catalyzed one-pot synthesis of hexahydroquinoline-3-carboxamide derivatives by the four-component reaction of arylaldehydes, dimedone, acetoacetanilide and ammonium acetate in high to excellent yield in ethanol at 70 ℃. The synthesized compounds were identified by FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. An environmentally benign procedure, short reaction time, high yields and biocompatible natural catalyst are some advantages of this research.
    Keywords: Unripe grape juice, Multi-component reactions, Pyranopyrazoles, Hexahydroquinoline-3-carboxamides
  • Akbar Rostami, Vartooni *, Abolfazl Moradi, Saadatmand, Mojtaba Bagherzadeh, Mohammad Mahdavi Pages 27-35
    In this work, at first, nano ZrO2 and Fe3O4/ZrO2 nanocomposite were prepared by sol-gel and co-precipitation methods, respectively. Then, Ag nanoparticles (Ag NPs) were mixed with themin environmentally friendly and mild conditions using C. cyanus flower extract as a reducing and stabilizing agent. The synthesized nanocomposites were characterized by FT-IR, XRD, FE-SEM, EDS, and VSM techniques. The experimental results confirmed formation of the Ag nanoparticles with the 30-90 nm diameter on the surface of supports at room temperature within a few minutes. After that, the catalytic activity of the prepared nanocomposites in reduction of 4-nitrophenol (4-NP) and methyl orange (MO) have been studied and our results showed that they have following sequence: Ag/ZrO2 > Ag/Fe3O4/ZrO2 > ZrO2 > ZrO2 (550 °C) > Fe3O4/ZrO2. Finally, the magnetically recoverable Ag/Fe3O4/ZrO2 nanocomposite could be reused three times without a considerable decrease in its catalytic activity. Observed results were presented here and the probable catalytic mechanism was discussed.
    Keywords: Centaurea cyanus, Ag Nanoparticles, Zirconia, Magnetic support, Green synthesis, Organic pollutant
  • Javad Afsar, Ardeshir Khazaei *, Mohammad Ali Zolfigol Pages 37-49
    1-Methyl-1H-imidazol-3-ium 2,3,4,5,6-pentafluorophenolate [mim]C6F5O as a novel nano ionic liquid was designed, synthesized and characterized by using various techniques such as Fourier transform spectroscopy infrared (FT-IR), nuclear magnetic resonance (NMR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), derivative thermal gravimetric (DTG) and elemental analysis (CHN). The described nano perfluoro ionic liquid was used as an efficient catalyst in the synthesis of 2-amino-4,5-dihydropyrano[3,2-c]chromene, 3-amino-1H-benzo[f]chromene and 2-amino-4H-chromene derivatives under mild and solvent-free conditions. Short reaction times, good yields of products, easy work-up are the major advantages of this work.
    Keywords: Nano perfluoro ionic liquid, [mim]C6F5O, 1-Methyl-1H-imidazol-3-ium-2, 3, 4, 5, 6-pentafluorophenolate, Chromenes, Solvent-free conditions
  • Zahra Alipour, Fereshteh Meshkani *, Mehran Rezaei Pages 51-61
    The kinetic characteristics of the Ni/Al2O3 and Ni/MgO-Al2O3 catalysts were investigated in CO2 reforming of methane (CRM). The reaction orders (α and β) and the rate constant (k) were calculated using the non-linear regression analysis, in which the sum of the squared differences of calculated and experimental CO2 reforming of methane rates were minimized. The acquired results demonstrate that the methane partial pressure has a significant influence on the reaction rate compared to the partial pressure of carbon dioxide in CRM and the reaction rate of MgO- modified catalyst was higher than the unmodified sample. This may be due to the higher catalytic activity of Ni/MgO-Al2O3 compared to that of Ni/Al2O3 in CRM. The activation energy for CH4 consumption was higher than that of CO2. Meanwhile, adding CO and H2 to the feed has a negative effect on the reaction rate. The experimental CH4 consumption rates for both Ni/Al2O3 and Ni/Mg-Al2O3 were fitted to some kinetic type models in order to investigate the effect of MgO modifier on the reaction kinetics of the Ni catalyst so the model with the lowest squared error was proposed as the best model describing the reaction rate.
    Keywords: Ni catalysts, CO2 reforming of methane, Kinetics, Synthesis gas
  • Baharak Divband, Azadeh Jodaei *, Masumeh Khatamian Pages 63-70
    In this paper, Ag/ZnO/HZSM-5ternary nanocomposites with different Ag loadings were prepared by the photo precipitation method. The prepared photocatalysts were characterized by XRD, BET, SEM and TEM. The photocatalytic activity of ZnO/HZSM-5 for 4-nitrophenol (4-NP) degradation was increased by silver doping. Effects of various parameters such as the initial concentration of 4-NP, pH and Ag loading on 4-NP degradation were studied. The best activities were obtained for the 3% Ag-10% ZnO/HZSM-5 nanocatalysts at pH 7.9, 1 g L−1 of the catalyst and 5 ppm of 4-NP. Langmuir–Hinshelwood (L–H) model was proposed for the rate equation of the 4-NP degradation.
    Keywords: Photo precipitation method, Ag, ZnO, HZSM-5, Ternary nanocomposites, Photocatalytic oxidation
  • Hannaneh Heidari *, Kobra Nikoofar, Yeganeh Shahedi Pages 71-77
    A novel and cost-effective catalyst for synthesis of 2,3'-dihydroquinazolin-4-(1H)-ones was developed utilizing a combined nanocomposite obtained from bonding TiCl3 to hydroxyl groups of nanofibrillated cellulose as a green and inexpensive support.The structure of the catalyst was investigated using the Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) techniques and transmission electron microscopy (TEM). The prepared new nanopolymer-based composite has been investigated successfully to obtain some 2,3'-dihydroquinazolin-4-(1H)-ones via the reaction of 2-aminobenzamide and various kinds of aldehydes/ cyclic ketones in refluxing ethanol. Short reaction times, the low amount of catalyst, high yields of products, utilizing a wide-range of aldehydes/ ketones, easy work-up procedure, in addition to the accelerating effect of the newly synthesized biodegradable nano composite, are some highlighted features of the reported protocol.
    Keywords: Nanofibrillated cellulose, Titanium chloride, Heterogeneous catalyst, 2, 3'-Dihydroquinazolin-4-(1H)-ones
  • Pranab Jyoti Das *, Dimpee Das Pages 79-83
    Pyridinium based ionic liquids derived from β-picoline and n-alkylbromides were synthesized by a simple procedure at ambient temperature and then characterized. These neutral ionic liquids were investigated for their dual role as the solvent and promoter for the selective synthesis of a series of N-monomethylanilines using dimethylcarbonate as the methylating agent. A solvent free green procedure was developed. Reaction conditions were mild and the product recovery was simple. Excellent selectivity for N-monomethylation, the high yield of the product and recyclability of the ionic liquids are some of the promising features of this protocol.
    Keywords: Dimethylcarbonate, Pyridinium ionic liquids, Anilines, N-monomethylanilines, Solvent-free reaction
  • Meysam Yarie * Pages 85-89
    Meysam Yarie was born in 1987 in Malayer/ Hamedan, Iran. He received his B.Sc. in Applied Chemistry from Malek-Ashtar University of Technology and M.Sc. in Organic Chemistry from Kurdistan University under the supervision of Dr. Kamal Amani. He received his Ph.D. from Bu-Ali Sina University under the supervision of Professor Mohammad Ali Zolfigol. He is currently working towards his Post-Doctoral under the supervision of Professor Mohammad Ali Zolfigol at Bu-Ali Sina University. His research interest is the design, synthesis and characterization of task-specific biological-based catalysts and their applications in organic synthesis.
    Keywords: Organic salts, Y-aromatic counter ions