نشریه شیمی کاربردی روز
پیاپی 45 (زمستان 1396)

The acidic ionic liquids, 2-pyrrolidonium hydrogensulfate, N-methyl-2-pyrrolidonium hydrogensulfate, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate and (4-sulfobutyl) tris (4-sulfophenyl) phosphonium hydrogensulfate catalyzed one-pot three-component condensation between aromatic aldehydes, substituted acetophenones, malononitrile and ammonium acetate to afford corresponding 2-amino-3-cyanopyridine derivatives. This synthetic method has the remarkable advantages such as mild reaction conditions and good isolated yields, short reaction time, and use of green catalysts.
The acidic ionic liquids, 2-pyrrolidonium hydrogensulfate, N-methyl-2-pyrrolidonium hydrogensulfate, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate and (4-sulfobutyl) tris (4-sulfophenyl) phosphonium hydrogensulfate catalyzed one-pot three-component condensation between aromatic aldehydes, substituted acetophenones, malononitrile and ammonium acetate to afford corresponding 2-amino-3-cyanopyridine derivatives. This synthetic method has the remarkable advantages such as mild reaction conditions and good isolated yields, short reaction time, and use of green catalysts.
The acidic ionic liquids, 2-pyrrolidonium hydrogensulfate, N-methyl-2-pyrrolidonium hydrogensulfate, triphenyl(propyl-3-sulphonyl)phosphonium toluenesulfonate and (4-sulfobutyl) tris (4-sulfophenyl) phosphonium hydrogensulfate catalyzed one-pot three-component condensation between aromatic aldehydes, substituted acetophenones, malononitrile and ammonium acetate to afford corresponding 2-amino-3-cyanopyridine derivatives. This synthetic method has the remarkable advantages such as mild reaction conditions and good isolated yields, short reaction time, and use of green catalysts.

Modified nanomagnetic acid catalyst SiO2/Fe3O4/SO3H was synthesized in simple method and used for synthesizing 2,4,5-tri substituted imidazole by combining three components such as benzil, aldehydes and ammonium acetate of which the last component was as an ammonia source. High yield of tri-substituted imidazole without significant loss of efficiency and easy recovery by an external magnetic field and several times of reusability with less deterioration are advantages of SiO2/Fe3O4/SO3H catalyst. A large amount of acid existing on the surface of the magnetic layer leads to more activities of the catalyst and as a result, the yielding of tri-substituted imidazole increases. The acidic functioned nanomagnetic core-shell catalyst was approved as per Fourier transfer infrared (FT-IR), X-ray diffraction powder (XRD), Energy dispersive X-Ray spectroscopy (EDS), Thermal gravimetric analysis (TGA), Vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM).

IIn this work we report a facile and green approach to synthesis of graphene nanosheets(GNS) supported Pt nanoparticles (Pt/GNS),in which graphene acts as a high surface area and conductive host for Pt nanoparticles for oxygen reduction reaction in fuel cells. Several phytochemicals extracted from different natural leaves of plants are employed as green and eco-friendly reducing agents in the synthesis of various silver, gold, platinum, and copper nanoparticles. In this study, Cherry leaf extracts were employed as a green reducing agent to reduce graphene oxide and Pt nanoparticles. The prepared Pt/GNS exhibits greatly enhanced electrochemical performance than commercial (ElectroChem Pt/C). These are attributed to the much graphitized degree of GNS in comparison to carbon black and the improved Pt-carbon interaction in Pt/GNS,high surface area and electrical conductivity of graphene support in Pt/GNS.

In this study activated carbon was synthesized from orange peel by ZnCl2 solution at 60 ºC for 12 h and then carbonized in a furnace at 475 ºC for 90 min. The treated sample was impregnated with iron (III) chloride solution in the presence of NaBH4 solution under a nitrogen atmosphere. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The effects of various parameters such as pH, contact time, initial nitrate concentration, and adsorbent dosage were investigated for efficient removal of nitrate. The results showed impregnation activated carbon with Fe improved the adsorption ability by nearly two times more compared to the pure one. Kinetics data indicate that the adsorption of nitrate follows pseudo-second order kinetics model. The adsorption data are found to fit well with Langmuir isotherm and the maximum adsorption capacities for activated carbon and Fe/ activated carbon were obtained 16.23 and 41.32 mg/g, respectively.

Silica vanadic acid (oxo-vanadium has been supported on silica) with Lewis and Bronsted acid site is introduced as an efficient, reusable, and heterogeneous catalyst for tandem Knoevenagel–Michael reaction of two equivalents of 5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one with various aromatic aldehydes for the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol)s at room temperature. The present methodology offers several advantages over existing methodologies, such as excellent yields, short reaction time, simple procedure, easy work-up, mild reaction conditions, and synthesis of wide range of products. This procedure gave the products in excellent yields within very short reaction times over other vanadium(V) compounds. Also this catalyst can be reused six times without appreciable loss of its catalytic activity.

In this study, the degradation of the two dyes basic in their binary mixture is examined under the light irradiation in the presence of catalyst. A mercury lamp, which was located at a distance 30 cm from the solution surface, was used as the UV irradiation source. The first-order derivative spectra was used to obtain the residual concentration of each dye in mixtures after a given time of photo-degradation. The and techniques are employed to confirm the nanocomposite prepared. The effects of the parameters involved in the photo-catalytic activity including the solution, catalyst dosage, and concentrations of the two dyes are studied. The results obtained show that under the optimum experimental conditions and after 60 minutes of the UV light irradiation in the presence of the 8 mg catalyst and in the of 5.5, the percentage degradation of the two dyes are more than 90%.

Intrinsically conducting polymers (ICPs) such as polyaniline and polypyrrole which have advantages such as high conductivity, high flexibility, ease synthesis routes, high stability and good mechanical properties, have aroused intense of many researches for various application such as electrolytic capacitors, electronic and electrochromic devices, sensors, light-weight batteries, membrane separation and radar absorbing materials (RAMs). In this research, polypyrrole (PPy) with novel morphology was synthesized successfully, using a microstructured MnO2 microcube as a self-reactive template and oxidizing agent for the beginning of the polymerization reaction. MnCO3 microcubes were synthesized by hydrothermal method at 150 °C. They were utilized as precursors for MnO2 microcube synthesis. XRD patterns of MnO2 and PPy revealed that the MnO2 templates consumed almost completely as an initiator or an oxidizing agent in polymerization reaction. Also, FESEM images demonstrated that PPy structures are totally inherited their morphologies from MnO2 templates.

In this paper, preparation of new Cu-Zn-Al spinel catalysts with CeO2 using sol-gel and homogeneous precipitation methods are reported. For evaluation of the prepared catalysts for steam reforming of methanol, an A-type micro-channel reactor was designed and fabricated and the prepared catalysts were coated on the reactor channels by hybrid method between sol-gel and suspension methods. The catalysts were evaluated at 270 ºC to 310 ºC. For the catalysts evaluation a mixture of methanol and water with 1.5, 2.5 and 3.5 molar ratios were used as the feed of the reactor. Flow rate of the feed was 2 cc/h. Obtained results show that the prepared spinel catalysts were promising catalysts for hydrogen production by methanol steam reforming. Also, by computational fluid dynamic the geometrical effects of micro-channels on velocity distribution for two different A-type and Z-type micro-channels were considered.

In this work degradation of Methylene blue (MB) was studied by sonofenton process (Fenton reagent剛歪쨮 irradiation). The effect of initial concentrations of H2O2, Fe2 and MB, initial pH of solution and ultrasound power on the degradation rate were investigated. The results show that the degradation rate of MB was increased with increasing the concentration of Fe2 and MB. The degradation rate was increased with increasing concentration of H2O2 up to 0.0001M but degradation rate was decreased by further increasing the concentration of H2O2. The pH effect was investigated in the range of 2.7–4.6 and the result show that degradation rate of MB was decreased by increasing the pH value. The order of reaction respect to each reactant was determined by initial rate method. The results show that the degradation efficiency of MB was increased with increasing the ultrasound power. The synergistic index was found to be 1.4 for Fenton reagent剛歪쨮 irradiation, which reveals that there is a considerable synergistic effect in this coupled system.

In this study, at first UV-curable urethane acrylate-Clay nanocomposites (UA/Clay) were synthesized, then the effects of nanoparticles on the thermal stability, mechanical properties and thermal conductivity of UA nanocomposites were investigated. FT-IR analysis confirmed the molecular structure of urethane acrylate oligomer. SEM images showed that the nanoparticles were dispersed uniformly in the polymer matrix. The thermal stability of samples were investigated by thermogravimetric analysis (DTG). DMTA study indicated significant improvement in the mechanical properties and thermal behavior of nanocomposites by adding a certain amount of Clay (3, 5 wt%) nanoparticles to polymer-matrix. Moreover, infrared thermography analysis showed that thermal conductivity of the nanocomposites rose as filler content increased (3, 5 wt%).

In this study, characterization of Co3O4 nanoparticle and Nd and Eu doped on the cobalt oxide were presented. Then, these nanoparticles were prepared by a combustion synthesis method for 8h at temperature 700 ºC using only complex Co(acac)3.Nanoparticles were characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental maps analysis, energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). The effect of neodymium and europium additive was also studied using cyclic voltammetry (CV) for the oxygen evolution reaction in an alkaline environment. Analysis of electrocatalytic activity for oxygen evolution reaction (OER) demonstrated that europium efficiency increased the oxygen evolution current. Meanwhile, neodymium has no effect on the properties of Co3O4 in this case.