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CHEMISTRY (583 journals)            First | 1 2 3 4 5 6 | Last

Journal of Catalysts     Open Access  
Journal of Chemical & Engineering Data     Full-text available via subscription   (Followers: 11)
Journal of Chemical and Biological Interfaces     Full-text available via subscription  
Journal of Chemical Education     Full-text available via subscription   (Followers: 18)
Journal of Chemical Health Risks     Open Access   (Followers: 2)
Journal of Chemical Information and Modeling     Full-text available via subscription   (Followers: 5)
Journal of Chemical Research     Full-text available via subscription   (Followers: 5)
Journal of Chemical Science and Technology     Open Access   (Followers: 3)
Journal of Chemical Sciences     Partially Free   (Followers: 17)
Journal of Chemical Theory and Computation     Full-text available via subscription   (Followers: 13)
Journal of Cheminformatics     Open Access   (Followers: 1)
Journal of Chemistry     Open Access   (Followers: 3)
Journal of Chemometrics     Hybrid Journal   (Followers: 10)
Journal of Chromatography A     Hybrid Journal   (Followers: 55)
Journal of Clinical Toxicology     Open Access   (Followers: 1)
Journal of Colloid and Interface Science     Hybrid Journal   (Followers: 14)
Journal of Computational Chemistry     Hybrid Journal   (Followers: 16)
Journal of Coordination Chemistry     Hybrid Journal   (Followers: 1)
Journal of Dispersion Science and Technology     Hybrid Journal  
Journal of Encapsulation and Adsorption Sciences     Open Access   (Followers: 4)
Journal of Environmental Chemistry and Ecotoxicology     Open Access   (Followers: 2)
Journal of Flow Chemistry     Full-text available via subscription   (Followers: 1)
Journal of Fluorescence     Hybrid Journal   (Followers: 4)
Journal of Fluorine Chemistry     Hybrid Journal   (Followers: 6)
Journal of Fuel Chemistry and Technology     Full-text available via subscription   (Followers: 5)
Journal of Great Lakes Research     Hybrid Journal   (Followers: 7)
Journal of Heterocyclic Chemistry     Hybrid Journal   (Followers: 5)
Journal of Immunoassay and Immunochemistry     Hybrid Journal   (Followers: 3)
Journal of Inclusion Phenomena and Macrocyclic Chemistry     Hybrid Journal   (Followers: 2)
Journal of Inorganic Biochemistry     Hybrid Journal   (Followers: 2)
Journal of Labelled Compounds and Radiopharmaceuticals     Hybrid Journal   (Followers: 1)
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry     Hybrid Journal   (Followers: 3)
Journal of Mass Spectrometry     Hybrid Journal   (Followers: 25)
Journal of Materials Chemistry A : Materials for Energy and Sustainability     Full-text available via subscription   (Followers: 26)
Journal of Materials Chemistry B : Materials for Biology and Medicine     Full-text available via subscription   (Followers: 6)
Journal of Materials Chemistry C : Materials for Optical, Magnetic and Electronic Devices     Full-text available via subscription   (Followers: 8)
Journal of Materials Physics and Chemistry     Open Access   (Followers: 1)
Journal of Materials Research     Full-text available via subscription   (Followers: 10)
Journal of Mathematical Chemistry     Hybrid Journal   (Followers: 6)
Journal of Medicinal Chemistry     Full-text available via subscription   (Followers: 88)
Journal of Membrane and Separation Technology     Hybrid Journal  
Journal of Membrane Science     Hybrid Journal   (Followers: 11)
Journal of Modern Chemistry & Chemical Technology     Full-text available via subscription   (Followers: 2)
Journal of Molecular Catalysis A: Chemical     Hybrid Journal   (Followers: 3)
Journal of Molecular Graphics and Modelling     Hybrid Journal   (Followers: 4)
Journal of Molecular Liquids     Hybrid Journal   (Followers: 1)
Journal of Molecular Modeling     Hybrid Journal   (Followers: 3)
Journal of Molecular Recognition     Hybrid Journal   (Followers: 2)
Journal of Molecular Spectroscopy     Hybrid Journal   (Followers: 7)
Journal of Molecular Structure     Hybrid Journal   (Followers: 3)
Journal of Nanoparticles     Open Access  
Journal of Nanostructure in Chemistry     Open Access   (Followers: 3)
Journal of Natural Gas Chemistry     Full-text available via subscription   (Followers: 2)
Journal of Nepal Chemical Society     Open Access  
Journal of Nucleic Acids Investigation     Open Access   (Followers: 2)
Journal of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 1)
Journal of Organometallic Chemistry     Hybrid Journal   (Followers: 14)
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 3)
Journal of Polymer & Composites     Full-text available via subscription   (Followers: 4)
Journal of Polymer and Biopolymer Physics Chemistry     Open Access   (Followers: 2)
Journal of Polymer Science Part A: Polymer Chemistry     Hybrid Journal   (Followers: 142)
Journal of Polymers     Open Access   (Followers: 1)
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 2)
Journal of Pure and Applied Chemistry Research     Open Access   (Followers: 1)
Journal of Raman Spectroscopy     Hybrid Journal   (Followers: 11)
Journal of Research Updates in Polymer Science     Hybrid Journal  
Journal of Saudi Chemical Society     Open Access  
Journal of Solid State Chemistry     Hybrid Journal   (Followers: 14)
Journal of Solution Chemistry     Hybrid Journal   (Followers: 4)
Journal of Structural Chemistry     Hybrid Journal  
Journal of Sulfur Chemistry     Hybrid Journal   (Followers: 2)
Journal of Superhard Materials     Hybrid Journal   (Followers: 1)
Journal of Surfactants and Detergents     Hybrid Journal   (Followers: 5)
Journal of Taibah University for Science     Open Access   (Followers: 1)
Journal of the American Chemical Society     Full-text available via subscription   (Followers: 222)
Journal of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 21)
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 1)
Journal of the Bangladesh Chemical Society     Open Access  
Journal of the Chilean Chemical Society     Open Access   (Followers: 2)
Journal of the Iranian Chemical Society     Hybrid Journal  
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal   (Followers: 1)
Journal of the Mexican Chemical Society     Open Access   (Followers: 1)
Journal of Theoretical and Computational Chemistry     Hybrid Journal   (Followers: 8)
Journal of Theoretical Chemistry     Open Access  
Journal of Wood Chemistry and Technology     Hybrid Journal   (Followers: 7)
JPC - Journal of Planar Chromatography - Modern TLC     Full-text available via subscription   (Followers: 5)
Jurnal Penelitian Sains (JPS)     Open Access  
Jurnal Teknologi Informasi     Open Access   (Followers: 3)
Karbala International Journal of Modern Science     Open Access  
Kinetics and Catalysis     Hybrid Journal   (Followers: 3)
Korea-Australia Rheology Journal     Hybrid Journal  
Langmuir     Full-text available via subscription   (Followers: 42)
Latvian Journal of Chemistry     Open Access   (Followers: 1)
Lebensmittelchemie     Hybrid Journal   (Followers: 1)
Lipid Insights     Open Access  
Luminescence     Hybrid Journal   (Followers: 1)
Macromolecular Materials & Engineering     Hybrid Journal   (Followers: 5)
Macromolecular Rapid Communications     Hybrid Journal   (Followers: 5)
Macromolecular Research     Hybrid Journal  

  First | 1 2 3 4 5 6 | Last

Journal Cover   Kinetics and Catalysis
  [SJR: 0.367]   [H-I: 21]   [3 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1608-3210 - ISSN (Online) 0023-1584
   Published by Springer-Verlag Homepage  [2280 journals]
  • Polymetallic catalysts for the Fischer–Tropsch synthesis and
           hydrodesulfurization prepared using self-propagating high-temperature
    • Abstract: Abstract The synthesis, physicochemical characteristics, and operation of the previously proposed new multifunctional polymetallic catalysts in reduction processes are considered. The complex intermetallides of 3d metals and rare-earth elements, which are obtained by self-propagating high-temperature synthesis (SHS), are catalyst precursors. The catalyst structure includes a framework of lower intermetallic compounds covered with a strongly disordered highly amorphous metal oxide active phase. This phase forms two-level nanostructures (~10–100 nm) with a characteristic shape of flat hexahedrons on the surface. The catalysts possess high activity in the reactions of deep oxidation and reduction (the Fischer–Tropsch synthesis and the hydrodesulfurization of petroleum fractions); moreover, they do not require preliminary activation in the reduction processes.
      PubDate: 2015-09-01
  • Selective catalytic reduction of NO over M–Ag/ZSM-5 bimetallic
           nanocatalysts (M = Mn, Fe and Ni). Physicochemical properties and
           catalytic performance
    • Abstract: Abstract Selective catalytic reduction of NO by ammonia in the presence of excess oxygen has been studied over monometallic Ag/ZSM-5 and bimetallic M–Ag/ZSM-5 (M = Mn, Fe and Ni) nanocatalysts. Ag/ZSM-5 shows a good activity but low selectivity to N2 and produces N2O in considerable amounts. To improve selectivity for N2 the Ag/ZSM-5 catalyst was modified by adding different transition metals (Mn, Fe and Ni). The Fe–Ag/ZSM-5 bimetallic nanocatalyst showed the highest activity (95% NO conversion and 73% selectivity to N2 at 300°C). X-ray diffraction, transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), ammonia temperature-programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy were applied to characterize Ag/ZSM5 and M–Ag/ZSM-5 nanocatalysts. TEM results revealed the presence of nano-sized Ag/metal oxide species on the H-ZSM-5 support in M–Ag/ZSM-5 catalysts and highly dispersed Ag/metal oxide species in the Fe–Ag/ZSM-5 catalyst. The NH3-TPD measurements confirmed that compared to other catalysts the Fe–Ag/ZSM-5 catalyst has an increased amount of strong acid sites and a higher NH3 storage capacity.
      PubDate: 2015-09-01
  • New method for regulating the activity of ABO 3 perovskite catalysts
    • Abstract: Abstract A new possibility of changing the activity and selectivity of perovskite catalysts in the oxidative conversion of methane was demonstrated using the Sr x Gd1–x CoO3–δ (0.5 < x < 0.9) compounds as an example. It was established that, at the same chemical composition, the disordering of Sr2+/Gd3+ ions over the A positions of the crystal structure led to a significant increase in activity in the deep oxidation reaction of CH4, as compared with the samples with an ordered distribution of cations.
      PubDate: 2015-09-01
  • Polymer-immobilized rhodium complexes forming in situ: preparation and
           catalytic properties
    • Abstract: Abstract We elaborated a method for frontal polymerization of a Rh-containing monomer in the presence of a conventional support to obtain polymer-immobilized hydrogenation catalysts. A hybrid nanocomposite forms during the propagation of a narrow molten zone (first-order phase transition) and is characterized by stable front propagation throughout the reaction volume. The products were characterized by various physicochemical methods and were tested as catalysts in the hydrogenation of cyclohexene, allyl alcohol, and nitrobenzene. The transformation of the X-ray photoelectron spectrum (XPS) on passing from the starting rhodium nitrate complex to its metal monomer (acrylamide complex), polymer, and supported catalyst is described. Native intermediate products were isolated and characterized by XPS.
      PubDate: 2015-09-01
  • Electrocatalytic layers based on reduced graphene oxide for fabrication of
           low-temperature fuel cells
    • Abstract: Abstract Reduced graphene oxide (rGO) with a specific surface area of ~600 m2/g has been synthesized and characterized. A series of membrane-electrode assemblies has been fabricated and tested as an element of a fuel cell. In the fabrication of these assemblies, rGO (0–10% of the weight of the Pt/Vulcan XC-72 electrocatalyst) was added to the electrocatalytic composition. The optimum rGO concentration in the active layer of a fuel cell is 5 wt %. At this rGO concentration, the specific power of the fuel cell is at least 20% higher than in the case of the rGO-free electrocatalytic layers.
      PubDate: 2015-09-01
  • The photocatalytic interaction of Cr(VI) ions and phenol on
           polymer-modified TiO 2 under visible light irradiation
    • Abstract: Abstract To investigate the interaction of Cr(VI) and phenol in the photocatalytic process, the photocatalytic reaction of the mixed solution of these two pollutants was carried out using poly(fluorene-co-thiophene) modified TiO2 photocatalyst and visible light. In this mixed system, the removal efficiency in the presence of Cr(VI) and phenol were higher than that produced by individual systems, indicating a synergetic effect between the reduction of Cr(VI) and degradation of phenol. In the mixed system, Cr(VI) ions were reduced by the photo-generated electrons, and phenol was oxidized by photo-generated holes. In the presence of Cr(VI) ions, both the photocatalytic degradation and mineralization efficiency of phenol were promoted, but the promoting role was not the same. There was an optimum value of phenol/Cr(VI) molar ratio (1: 1) in the degradation process. If the ratio was less than 1 : 1, the promoting effect decreased slowly but was still fairly distinct. The mineralization efficiency of phenol increased gradually with the increasing concentration of Cr(VI) ions, but when phenol/Cr(VI) was less than 1 : 1, the rate of increase became slower.
      PubDate: 2015-09-01
  • CO 2 hydrogenation over cobalt-containing catalysts
    • Abstract: Abstract Carbon dioxide hydrogenation over catalysts consisting of 0.56–45 wt % cobalt supported on carbon nanotubes (CNTs), carbon nanofibers, few-layer graphite fragments, or CNTs–Al2O3 composites has been investigated. All of the Co/support catalytic systems have been characterized by temperature-programmed reduction, transmission electron microscopy, and scanning electron microscopy. Under the conditions of our catalytic experiment (1 atm, 180–500°C), the CO2 hydrogenation products are CH4 and/or CO and the activity of the catalysts depends on the size and phase state of the cobalt particles. The CNTs-supported materials containing less than 5 wt % Co are catalytically inactive because of the amorphism of the metal. They can be activated by cobalt crystallization by means of heat treatment. The size of the cobalt particles deposited on the carbon supports is about 4 nm. Methods of functionalizing the carbon nanomaterial surface for additional stabilization of metal nanoparticles are suggested.
      PubDate: 2015-09-01
  • Synthesis of membrane catalysts based on Mo 2 C
    • Abstract: Abstract Versions of the synthesis of composite membrane catalysts based on Mo2C and ceramic microfiltration membranes by chemical vapor deposition and a sol–gel method were developed. The samples of massive and supported membrane catalysts were prepared. Differences in the formation of a catalytic layer and its porous structure depending on the sample preparation method were demonstrated. The catalytic activity of the synthesized samples in the carbon dioxide conversion reaction of methane was studied.
      PubDate: 2015-09-01
  • Trinuclear tantalum clusters grafted to hydroxylated silica surfaces: A
           density-functional embedded-cluster study
    • Abstract: Abstract To identify the coordination modes of bare and hydrogenated trinuclear tantalum species on hydroxylated silica, we computationally examined models of Ta3H n (n = 0, 3, 5–9) species grafted to a β-cris-tobalite surface. Ta3H n clusters are bound to the surface by substitution of hydrogen atoms of vicinal (…O-)3SiOH and geminal (…O-)2Si(OH)2 groups via three and six, respectively, Ta–O bonds of ~193 pm on average, in both types of models. The maximum Ta–O coordination number of non-hydrogenated Ta3 species to a silica surface is seven for the second type model surface; the additional Ta–O bond is due to an oxygen atom located in a bridging position to Ta–Ta bond. In the latter case, the mean Ta–O bond distance to one of =Si(O–)2 group is increased by 15 pm. For the complexes bound via vicinal silanol groups, each additional unit of hydrogen loading on the metal elongated the average Ta–Ta distance by ~2 pm, covering a range of 258–277 pm. For the most stable hydrogenated trimers, Ta3H9, the desorption energies of hydrogen atoms are relatively high, above 70 kJ/mol. The average Ta–Ta distances increase by ~19 pm on going from the complex (=SiO–)3Ta3H9 to complex (=SiO–)3Ta3 and by ~5 pm when the hydrogen loading is increased by one unit for (=Si(O–)2)3Ta3H n complexes, reaching the maximum value 319 pm when n = 9. The desorption energies of hydrogen atoms for the most stable tantalum trimer species grafted to the surface by geminal silanol groups, (=Si(O–)2)3Ta3H7, are rather low, less than 40 kJ/mol.
      PubDate: 2015-09-01
  • Kinetics, mechanism, and mathematical model of the reaction between uracil
           and hydrogen peroxide in aqueous solution
    • Abstract: Abstract The kinetics and mechanism of the reaction between uracil and hydrogen peroxide in aqueous solution have been investigated. Iron ion admixtures in the solution have been demonstrated to bring about two reaction pathways, one free-radical and the other molecular. The mechanism of the reaction has been analyzed by mathematical modeling methods, kinetic curves illustrating the variation of intermediate product concentrations have been obtained, and the rate constants of elementary reactions have been calculated.
      PubDate: 2015-09-01
  • Origin of temperature oscillations of nickel catalyst occurring in methane
    • Abstract: Abstract The catalytic oxidation of methane over a nickel foil has been investigated in a wide range of methane: oxygen molar ratios at a constant reactor temperature of 680°C. Under oxygen-deficient conditions, the reaction takes place in the self-oscillating mode. Stable self-sustained oscillations of the methane oxidation rate are observed in the CH4: O2 molar ratio range from 2: 1 to 19: 1. This process is accompanied by catalyst temperature oscillations, whose amplitude reaches 80°C. It has been demonstrated by scanning electron microscopy that the origination of the self-sustained oscillations is accompanied by morphological changes in the catalyst surface. Under the action of the reaction medium, a porous layer 5–10 µm in thickness forms on the nickel foil surface. The mechanism of methane oxidation over nickel that accounts for the onset of the self-sustained oscillations is discussed. This mechanism is based on periodical nickel oxidation and reduction. When nickel is in the high-activity state, it is mainly in metallic form, and the passage of nickel into its low-activity state is accompanied by the formation of a nickel oxide layer on the foil surface. The reduction of this nickel oxide causes a periodic decrease in the catalyst temperature. The total and partial oxidations of methane on the reduced surface of the nickel foil raise the catalyst temperature. Under oxygen-deficient conditions, a carbon deposit builds up on the catalyst surface, and the combustion of this deposit complicates the catalyst temperature oscillation profile.
      PubDate: 2015-09-01
  • Preparation of platinum compositions supported on reduced graphite oxide
           and their catalytic properties in liquid-phase hydrogenation
    • Abstract: Abstract Platinum compositions supported on graphite oxide prereduced by NaBH4 or N2H4 · H2O have been prepared. Platinum has been precipitated from H2PtCl6 solutions in the presence of pyridine onto reduced graphite oxide and has been reduced there by NaBH4. The resulting compositions, with a platinum particle size of ~2 nm, catalyze the hydrogenation of the–NO2 group in nitrobenzene and of the C=C double bond in dec-1-ene or styrene. The activity of the catalysts prepared by platinum precipitation on the prereduced graphite oxide is higher than that of platinum supported on unreduced graphite oxide. The high activity of the catalysts is assumed to be due to the localization of platinum on defects of the support structure.
      PubDate: 2015-09-01
  • Preparation of catalysts for the Fischer–Tropsch synthesis by the
           deposition of cobalt reduced with NaBH 4 onto a support
    • Abstract: Abstract A new method for the preparation of catalysts for the Fischer–Tropsch synthesis is proposed; it consists in the deposition of cobalt metal on a support at the instant of reduction from salts with a solution of NaBH4. The catalysts thus prepared are stable in air, and they do not require further high-temperature activation by hydrogen. The specific rate of CO conversion was 3.4–3.7 molCO mol-1 Co h–1; the selectivity for higher hydrocarbons was up to 88 mol %, and the hydrocarbon chain growth index α was up to 0.87.
      PubDate: 2015-09-01
  • Kinetics of the thermocatalytic conversion of lignocellulose
    • Abstract: Abstract The catalytic effect of variable-valence metal oxides on the thermal conversion of lignocellulose has been investigated by thermogravimetric analysis. Kinetic parameters of lignocellulose pyrolysis (in an argon atmosphere) and gasification (in a CO2 or steam medium) have been calculated by the Coats–Redfern method. A mechanism for the action of the oxide catalysts in the thermal conversion of lignocellulosic feedstock has been deduced from kinetic data.
      PubDate: 2015-09-01
  • Pd–Cu catalysts from acetate complexes in liquid-phase
           diphenylacetylene hydrogenation
    • Abstract: Abstract Properties of Pd–Cu/Al2O3 catalysts prepared using PdCu(CH3CO2)4 acetate heteronuclear complexes as precursors in the liquid-phase diphenylacetylene (DPA) hydrogenation have been studied. It has been established that the reaction over the Pd–Cu/Al2O3 catalyst proceeds more selectively than over the commercial Lindlar catalyst; in addition, high activity is achieved at a substantially lower palladium content. The maximum selectivity of DPA hydrogenation is observed with the catalyst reduced in a hydrogen atmosphere without any intermediate calcination that can result in the destruction of the bimetallic acetate complex. FTIR spectroscopy data for adsorbed CO show that the high selectivity of hydrogenation is due to the formation of homogeneous Pd–Cu particles and to the absence of monometallic palladium particles. This can be explained by the retention of the initial complex structure at all of the catalyst preparation stages until the formation of bimetallic particles during hydrogenation.
      PubDate: 2015-09-01
  • Study of Pt/MgAlO x catalysts in n -decane dehydrogenation
    • Abstract: Abstract The properties of Pt/MgAlO x catalysts based on aluminum–magnesium layered hydroxides have been investigated in n-decane dehydrogenation. The n-decene formation selectivity depends on the Mg/Al ratio in the support, on the platinum complex binding conditions, and on the platinum content of the catalyst. Increasing the proportion of magnesium decreases the number of acid cites in the support and changes the properties of supported platinum. As a result, the n-decene formation selectivity under the appropriate conditions reaches 90% without a modifier added.
      PubDate: 2015-09-01
  • Structural, textural, and acid–base properties of layered
           Mg–Al oxides modified with a tungstate or phosphate and their
           activity and selectivity in gas-phase glycerol dehydration
    • Abstract: Abstract The effect of the nature of the anion (WO2- 4, [H2W12O40]6–, HPO2- 4) introduced into the interlayer space of Mg–Al hydroxides with Mg/Al = 3 on their structural, textural, acid–base, and catalytic properties has been investigated. The synthesized materials are layered Mg–Al hydroxides with a hydrotalcite-like structure. Heat treatment of these hydroxides at 450–600°C yields a MgO-based solid solution, which turns into a mixture of MgO and MgAl2O4 phases on being heat-treated at 900°C. The samples modified with the [H2W12O40]6– and HPO2- 4 anions additionally contain MgWO4 and Mg3(PO4)2 phases, respectively. The OH groups of the materials examined do not show pronounced Brønsted acidity. (NH4)2HPO4 introduced into the interlayer space of the Mg–Al hydroxide is the most effective modifier enhancing the surface acidity, while the highest basicity is attained by introducing the Na2WO4 modifier. Glycerol dehydration at 275–350°C, involving acid sites of the surface, yields a wide variety of products containing 2 to 12 carbon atoms per molecule. A correlation has been established between the amount of glycerol dehydration products (acrolein + acetol) and the number of strong Lewis acid sites (νCO = 2177–2195 cm–1). The presence of basic sites varying in strength and concentration on the catalyst surface is favorable for condensation, cyclization, and oligomerization reactions yielding a wide range of C4+ products.
      PubDate: 2015-09-01
  • Functions of organoaluminum and proton donor compounds in the formation
           and functioning of nanosized Ziegler-type nickel-containing hydrogenation
    • Abstract: Abstract The turnover frequency (TOF) and turnover number (TON) in styrene hydrogenation have been determined for catalytic systems based on Ni(acac)2 · nH2O (n = 0, 0.5, and 3.0), Ni(COD)2 (COD = cycloocta-1,5-diene), and AlEt3 at different Al/Ni molar ratios. The amount of water of crystallization determines the TON and TOF of the nickel catalysts and their dependence on the Al/Ni ratio. The TON and TOF of the nickel catalysts are markedly increased by the introduction of an optimum amount of a proton donor. The model of the ligand shell stabilizing the nickel nanoparticles has been refined. The refined model provides an explanation for the activating action of proton donor compounds in the formation of the hydrogenation catalysts. The functions of the organoaluminum compounds are not limited to Ni(II) reduction to Ni(0); they are also involved in the stabilization of the nickel-containing nanoparticles.
      PubDate: 2015-09-01
  • Kinetic study of esterification of acetic acid with methanol over Indion
           190 acidic solid catalyst
    • Abstract: Abstract Esterification of acetic acid with methanol to synthesize methyl acetate in an isothermal well-mixed batch reactor was studied in the temperature range of 323.15–353.15 K. Indion 190 ion-exchange resin was used as a solid catalyst. Feed molar ratios were varied from 1: 1 to 1: 4. The influence of temperature, catalyst loading, stirring rate, catalyst particle size and initial molar ratio on the reaction rate was investigated. Experimental results showed that the reaction is kinetically controlled. The sorption experiments were carried out independently to find the adsorption constants. For the constituent components the values of adsorption constants decrease in the order of water > methanol > acetic acid > methyl acetate. The kinetic data were correlated with the pseudo-homogeneous (ideal and non-ideal), Eley-Rideal and Langmuir-Hinshelwood-Hougen-Watson (LHHW) models to determine the kinetic parameters. All the models were suitable to predict the experimental data, but with the LHHW model a more accurate match of the experimental data was achieved.
      PubDate: 2015-07-01
  • Model sulfur-resistant NSR catalysts: An XPS study of the interaction of
           BaO/TiO 2 -ZrO 2 and Pt-BaO/TiO 2 -ZrO 2 with NO 2
    • Abstract: Abstract The interaction of NO2 with BaO/TiO2-ZrO2 and Pt-BaO/TiO2-ZrO2 model NO x storage-reduction (NSR) catalysts prepared on the surface of FeCrAl alloy substrates has been investigated by X-ray photoelectron spectroscopy. The action of nitrogen dioxide on these catalysts at room temperature causes the consecutive formation of surface barium nitrite and nitrate. Supposedly, NO2 reduction yielding barium nitrite at the early stages of the interaction is due to the oxidation of amorphous carbon impurities. The introduction of platinum into the catalyst accelerates nitrogen dioxide sorption. On being exposed to NO2 for a long time, platinum oxidizes to PtO2. This process is more pronounced in the sample containing freshly deposited platinum. Heat treatment of this sample in a vacuum, which coarsens the platinum particles, makes them more resistant to oxidation.
      PubDate: 2015-07-01
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