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To handle huge amount of glycerol produced in biodiesel industry, glycerol is transformed to value-added products. In this regard, glycerol acetalization to solketal is industrially attractive. As in this process various by-products can be formed, designing highly selective catalysts is of great importance. In this line, we wish to report a novel catalyst that benefits from strong acidity, high specific surface area and thermal stability, which can selectively form solketal in glycerol acetalization. To prepare the catalyst, hierarchical zeolite was prepared via a novel method, in which partially dealuminated NaY was treated with PluronicF-127 and then reacted with NH4NO3 to furnish the H-form zeolite. Hierarchical faujasite was then achieved through calcination and template removal. Subsequently, it was functionalized with ionic liquid and used for the immobilization of heteropolyacid. The results indicated the importance of the mesoprosity of zeolite and the presense of ionic liquid functionality for achiveing high solketal yield. Moreover, among three investigated heteropolyacids, phosphomolybdic acid exhibited the highest catalytic activity. In fact, using 10 wt% catalyst at 55 °C and glycerol to acetone molar ratio of 1:20, solketal with yield of 98% was furnished under solvent-less condition. Besides, the catalyst was recyclable with low leaching of heteropolyacid. [ABSTRACT FROM AUTHOR]

In the present study, four different binders including two synthesized alumina-silica sol and two commercially available binders comprising LUDOX AS-30 colloidal silica and LUDOX AS-40 colloidal silica have been applied for preparation of FCC catalyst. Other catalyst components were included such as USY zeolite, kaolin, alumina, ZSM-5 zeolite and cerium nitrate. Four catalysts have been synthesized through spray drying of aqueous slurries of the components. The influence of different binders on the cracking performance and product distribution of FCC catalysts as well as their morphology has been investigated. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray powder diffraction, ammonia temperature-programmed desorption, inductive coupled plasma, Brunauer-Emmett-Teller and Barrett-Joyner-Halenda analysis have been operated to characterize the prepared catalysts. The reasonable spherical shaped particles of 40-50 μm size were obtained applying the synthesized alumina-silica sol and LUDOX-AS-40 colloidal silica as binder. The cracking activity of the prepared FCC catalysts was investigated in catalytic cracking of vacuum gas oil in a microactivity test unit and compared with the commercially available FCC catalyst. The results indicated that the synthesized catalysts have excellent activity with respect to the commercial one in terms of maximizing gasoline yields along with less alkanes production. The reusability of the catalysts was examined in four repeated cycles. [ABSTRACT FROM AUTHOR]

MnCo2O4 spinel nanoparticles (NPs) have been prepared using Aloe vera gel solution. The characterization of prepared spinel was performed applying Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, transmission electron spectroscope, scanning electron microscope and dynamic light scattering. The results manifested that the prepared nanoparticles were mainly spherical plus minor agglomeration with average size distribution between 35 and 60 nm. The catalytic activity of the prepared nanoparticles upon thermal degradation of ammonium perchlorate (AP) was evaluated applying differential scanning calorimetry and thermogravimetry instruments. MnCo2O4 nanoparticles increased the released heat of AP from 450 to 1480 J g−1 and decreased the decomposition temperature from 420 to 293 °C. The kinetic parameters obtained from Kissinger methods showed that the activation energy of AP thermal decomposition in the presence of MnCo2O4 NPs considerably decreased. Also, a mechanism has been proposed in the presence of catalyst for the process of thermal decomposition of AP. [ABSTRACT FROM AUTHOR]

Reaction of terephthalic acid and pyrazine with nickel nitrate under hydrothermal conditions forms a 3D metal-organic framework with the composition of [Ni(μ− tp)(μ− pyz)] ( 1), where Htp = 1,4-benzenedicarboxylic acid (terephthalic acid) and pyz = pyrazine. X-ray single crystal analysis reveals that Ni(II) centers adopt a distorted octahedral geometry which are surrounded by four oxygen atoms from three tp groups and two nitrogen atoms of pyrazine molecules in equatorial and axial positions, respectively. Coordination of Ni(II) centers by terephthalate linkers in ac plane forms infinite (4, 4)-connected 2D layers, which are further joined together by pyrazine groups to form an interlocked 3D structure. Topological studies show a two-fold interpenetrated uninodal 3D network with point symbol of (4·6). The polymer shows a blue emission band at 467 nm in the solid state at room temperature. The X-ray power diffractions (PXRD) and thermal gravimetric analysis of 1 are also presented and discussed. NiO nanoparticles have been prepared via direct calcination of 1 at 600 °C, with sizes of about 35-45 nm. Nanoparticles were further characterized by IR, scanning electron microscopy equipped with energy dispersive X-ray analyses and PXRD technique. [ABSTRACT FROM AUTHOR]

A metal-organic framework complex, [Co(μ-tp)(μ−pyz)], where Htp = 1,4-benzenedicarboxylic acid (terephthalic acid) and pyz = pyrazine, has been synthesized under hydrothermal conditions and characterized by physico-chemical and spectroscopic methods, thermogravimetric analysis and single-crystal X-ray diffraction. Each Co(II) center is surrounded by four carboxylate oxygen atoms from three tp ligands and two nitrogen atoms from two pyrazine ligands, giving a distorted octahedral geometry. The entire framework is made up of two-dimensional sheets of dicobalt ions linked via terephthalate ligands to form rectangles. The sheets are then linked into each other via the axial pyrazine ligands, forming an interlocked 3-D network, which is finally arranged as an ABAB interconnected pattern. Photoluminescence measurements for the polymer in the solid state show an emission at 414 nm, which suggests this complex as a potential blue-light material. The electrochemical behavior of a modified carbon paste electrode prepared from the complex has been studied by cyclic voltammetry, indicating quasi-reversible redox behavior. [ABSTRACT FROM AUTHOR]