Subjects -> MATHEMATICS (Total: 1028 journals)
    - APPLIED MATHEMATICS (92 journals)
    - GEOMETRY AND TOPOLOGY (23 journals)
    - MATHEMATICS (729 journals)
    - MATHEMATICS (GENERAL) (45 journals)
    - NUMERICAL ANALYSIS (26 journals)
    - PROBABILITIES AND MATH STATISTICS (113 journals)

MATHEMATICS (729 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 538 Journals sorted alphabetically
Abakós     Open Access   (Followers: 2)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 1)
Accounting Perspectives     Full-text available via subscription   (Followers: 4)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 13)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 5)
ACM Transactions on Mathematical Software (TOMS)     Hybrid Journal   (Followers: 6)
ACS Applied Materials & Interfaces     Hybrid Journal   (Followers: 38)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 2)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 5)
Acta Mathematica Vietnamica     Hybrid Journal  
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal  
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 5)
Advances in Catalysis     Full-text available via subscription   (Followers: 7)
Advances in Complex Systems     Hybrid Journal   (Followers: 10)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 20)
Advances in Decision Sciences     Open Access   (Followers: 4)
Advances in Difference Equations     Open Access   (Followers: 2)
Advances in Fixed Point Theory     Open Access  
Advances in Geosciences (ADGEO)     Open Access   (Followers: 19)
Advances in Linear Algebra & Matrix Theory     Open Access   (Followers: 9)
Advances in Materials Science     Open Access   (Followers: 19)
Advances in Mathematical Physics     Open Access   (Followers: 5)
Advances in Mathematics     Full-text available via subscription   (Followers: 18)
Advances in Numerical Analysis     Open Access   (Followers: 4)
Advances in Operations Research     Open Access   (Followers: 13)
Advances in Operator Theory     Hybrid Journal  
Advances in Pure Mathematics     Open Access   (Followers: 8)
Advances in Science and Research (ASR)     Open Access   (Followers: 8)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2)
African Journal of Educational Studies in Mathematics and Sciences     Full-text available via subscription   (Followers: 7)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 5)
Afrika Matematika     Hybrid Journal   (Followers: 2)
AKSIOMATIK : Jurnal Penelitian Pendidikan dan Pembelajaran Matematika     Open Access  
Al-Jabar : Jurnal Pendidikan Matematika     Open Access  
Al-Qadisiyah Journal for Computer Science and Mathematics     Open Access   (Followers: 3)
AL-Rafidain Journal of Computer Sciences and Mathematics     Open Access   (Followers: 3)
Algebra and Logic     Hybrid Journal   (Followers: 7)
Algebra Colloquium     Hybrid Journal   (Followers: 1)
Algebra Universalis     Hybrid Journal   (Followers: 2)
Algorithmic Operations Research     Open Access   (Followers: 5)
Algorithms     Open Access   (Followers: 13)
Algorithms Research     Open Access   (Followers: 1)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 8)
American Journal of Mathematical Analysis     Open Access   (Followers: 1)
American Journal of Mathematical and Management Sciences     Hybrid Journal  
American Journal of Mathematics     Full-text available via subscription   (Followers: 8)
American Journal of Operations Research     Open Access   (Followers: 7)
American Mathematical Monthly     Full-text available via subscription   (Followers: 3)
An International Journal of Optimization and Control: Theories & Applications     Open Access   (Followers: 12)
Analele Universitatii Ovidius Constanta - Seria Matematica     Open Access  
Analysis and Applications     Hybrid Journal   (Followers: 2)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 9)
Anargya : Jurnal Ilmiah Pendidikan Matematika     Open Access  
Annales Mathematicae Silesianae     Open Access  
Annales mathématiques du Québec     Hybrid Journal   (Followers: 3)
Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica     Open Access   (Followers: 1)
Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica     Open Access  
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 14)
Annals of Functional Analysis     Hybrid Journal   (Followers: 2)
Annals of Mathematics     Full-text available via subscription   (Followers: 3)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 16)
Annals of PDE     Hybrid Journal  
Annals of Pure and Applied Logic     Open Access   (Followers: 4)
Annals of the Alexandru Ioan Cuza University - Mathematics     Open Access  
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1)
Annals of West University of Timisoara - Mathematics     Open Access   (Followers: 1)
Annals of West University of Timisoara - Mathematics and Computer Science     Open Access   (Followers: 1)
Annuaire du Collège de France     Open Access   (Followers: 6)
ANZIAM Journal     Open Access   (Followers: 1)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 3)
Applications of Mathematics     Hybrid Journal   (Followers: 2)
Applied Categorical Structures     Hybrid Journal   (Followers: 3)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 16)
Applied Mathematics     Open Access   (Followers: 7)
Applied Mathematics     Open Access   (Followers: 6)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 10)
Applied Mathematics - A Journal of Chinese Universities     Hybrid Journal   (Followers: 1)
Applied Mathematics and Nonlinear Sciences     Open Access  
Applied Mathematics Letters     Full-text available via subscription   (Followers: 1)
Applied Mathematics Research eXpress     Hybrid Journal   (Followers: 1)
Applied Network Science     Open Access   (Followers: 2)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 4)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Arab Journal of Mathematical Sciences     Open Access   (Followers: 3)
Arabian Journal of Mathematics     Open Access   (Followers: 1)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4)
Archive of Numerical Software     Open Access  
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
Armenian Journal of Mathematics     Open Access  
Arnold Mathematical Journal     Hybrid Journal   (Followers: 1)
Artificial Satellites     Open Access   (Followers: 19)
Asia-Pacific Journal of Operational Research     Hybrid Journal   (Followers: 3)
Asian Journal of Algebra     Open Access   (Followers: 1)
Asian Research Journal of Mathematics     Open Access  
Asian-European Journal of Mathematics     Hybrid Journal   (Followers: 2)
Australian Mathematics Teacher, The     Full-text available via subscription   (Followers: 7)
Australian Primary Mathematics Classroom     Full-text available via subscription   (Followers: 4)
Australian Senior Mathematics Journal     Full-text available via subscription   (Followers: 1)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Baltic International Yearbook of Cognition, Logic and Communication     Open Access   (Followers: 2)
Banach Journal of Mathematical Analysis     Hybrid Journal  
Basin Research     Hybrid Journal   (Followers: 6)
BIBECHANA     Open Access  
Biomath     Open Access  
BIT Numerical Mathematics     Hybrid Journal  
Boletim Cearense de Educação e História da Matemática     Open Access  
Boletín de la Sociedad Matemática Mexicana     Hybrid Journal  
Bollettino dell'Unione Matematica Italiana     Full-text available via subscription  
British Journal for the History of Mathematics     Hybrid Journal  
British Journal of Mathematical and Statistical Psychology     Full-text available via subscription   (Followers: 17)
Bruno Pini Mathematical Analysis Seminar     Open Access  
Buletinul Academiei de Stiinte a Republicii Moldova. Matematica     Open Access   (Followers: 1)
Bulletin des Sciences Mathamatiques     Full-text available via subscription   (Followers: 3)
Bulletin of Dnipropetrovsk University. Series : Communications in Mathematical Modeling and Differential Equations Theory     Open Access   (Followers: 2)
Bulletin of Mathematical Sciences     Open Access   (Followers: 1)
Bulletin of Symbolic Logic     Full-text available via subscription   (Followers: 3)
Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics     Open Access  
Bulletin of the Australian Mathematical Society     Full-text available via subscription   (Followers: 2)
Bulletin of the Brazilian Mathematical Society, New Series     Hybrid Journal  
Bulletin of the Iranian Mathematical Society     Hybrid Journal  
Bulletin of the London Mathematical Society     Hybrid Journal   (Followers: 2)
Bulletin of the Malaysian Mathematical Sciences Society     Hybrid Journal  
Cadernos do IME : Série Matemática     Open Access  
Calculus of Variations and Partial Differential Equations     Hybrid Journal  
Canadian Journal of Mathematics / Journal canadien de mathématiques     Hybrid Journal  
Canadian Journal of Science, Mathematics and Technology Education     Hybrid Journal   (Followers: 20)
Canadian Mathematical Bulletin     Hybrid Journal  
Carpathian Mathematical Publications     Open Access  
Catalysis in Industry     Hybrid Journal  
CEAS Space Journal     Hybrid Journal   (Followers: 6)
CHANCE     Hybrid Journal   (Followers: 5)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 1)
Chaos, Solitons & Fractals : X     Open Access   (Followers: 1)
ChemSusChem     Hybrid Journal   (Followers: 7)
Chinese Annals of Mathematics, Series B     Hybrid Journal  
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Mathematics     Open Access  
Ciencia     Open Access  
CODEE Journal     Open Access  
Cogent Mathematics     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 2)
Collectanea Mathematica     Hybrid Journal  
College Mathematics Journal     Hybrid Journal   (Followers: 3)
COMBINATORICA     Hybrid Journal  
Combinatorics, Probability and Computing     Hybrid Journal   (Followers: 4)
Combustion Theory and Modelling     Hybrid Journal   (Followers: 18)
Commentarii Mathematici Helvetici     Hybrid Journal  
Communications in Advanced Mathematical Sciences     Open Access  
Communications in Combinatorics and Optimization     Open Access  
Communications in Contemporary Mathematics     Hybrid Journal  
Communications in Mathematical Physics     Hybrid Journal   (Followers: 2)
Communications On Pure & Applied Mathematics     Hybrid Journal   (Followers: 5)
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Complex Variables and Elliptic Equations: An International Journal     Hybrid Journal  
Compositio Mathematica     Full-text available via subscription  
Comptes Rendus : Mathematique     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 3)
Computational and Mathematical Methods     Hybrid Journal  
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 1)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 11)
Computational Methods and Function Theory     Hybrid Journal  
Computational Optimization and Applications     Hybrid Journal   (Followers: 9)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 8)
Confluentes Mathematici     Hybrid Journal  
Constructive Mathematical Analysis     Open Access  
Contributions to Discrete Mathematics     Open Access  
Contributions to Game Theory and Management     Open Access  
COSMOS     Hybrid Journal   (Followers: 1)
Cross Section     Full-text available via subscription   (Followers: 1)
Cryptography and Communications     Hybrid Journal   (Followers: 10)
Cuadernos de Investigación y Formación en Educación Matemática     Open Access  
Cubo. A Mathematical Journal     Open Access  
Current Research in Biostatistics     Open Access   (Followers: 8)
Czechoslovak Mathematical Journal     Hybrid Journal  
Daya Matematis : Jurnal Inovasi Pendidikan Matematika     Open Access  
Demographic Research     Open Access   (Followers: 14)
Design Journal : An International Journal for All Aspects of Design     Hybrid Journal   (Followers: 33)
Desimal : Jurnal Matematika     Open Access  
Dhaka University Journal of Science     Open Access  
Differential Equations and Dynamical Systems     Hybrid Journal   (Followers: 2)
Differentsial'nye Uravneniya     Open Access  
Digital Experiences in Mathematics Education     Hybrid Journal   (Followers: 2)
Discrete Mathematics     Hybrid Journal   (Followers: 8)
Discrete Mathematics & Theoretical Computer Science     Open Access   (Followers: 1)
Discrete Mathematics, Algorithms and Applications     Hybrid Journal   (Followers: 2)
Discussiones Mathematicae - General Algebra and Applications     Open Access  
Discussiones Mathematicae Graph Theory     Open Access   (Followers: 1)
Diskretnaya Matematika     Full-text available via subscription  
Doklady Akademii Nauk     Open Access  
Doklady Mathematics     Hybrid Journal  
Eco Matemático     Open Access  
Econometrics     Open Access   (Followers: 2)

        1 2 3 4 | Last

Similar Journals
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Catalysis in Industry
Journal Prestige (SJR): 0.258
Citation Impact (citeScore): 1
Number of Followers: 0  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2070-0555 - ISSN (Online) 2070-0504
Published by Springer-Verlag Homepage  [2469 journals]
  • Promotion of Supported Sulfated Zirconia Catalysts with Iron and Manganese
           Sulfates

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      Abstract: The effect of iron and manganese additives on the textural characteristics and phase composition of the alumina matrix support was studied for sulfated zirconia catalysts of hexane isomerization. The additives introduced at the stage of plastification of aluminum hydroxide significantly improved the catalyst activity (hexane conversion and selectivity of isomerization to hexane isomers). A distinction of the modified catalysts is the formation of acid sites in a ratio of LAS : BAS ≥ 2, which increase the yield of isomers and especially of high-octane 2,2-dimethylbutane.
      PubDate: 2021-10-01
       
  • Selective Catalytic Hydrogenation of Triple Bonds in Acetylenic Alcohols
           in a Microcapillary Reactor for Processes of Fine Organic Synthesis

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      Abstract: A report is given on the recent advances in the design, synthesis, and development of a new catalytic microreactor for the selective and continuous synthesis of value-added substances used in fine organic synthesis and pharmaceutical industry. Inside this advanced reactor, metal nanoparticles are incorporated into mesoporous materials that are deposited as very active and selective catalytic films on the walls of capillary microchannels with diameters of 220 and 530 µm. These microreactor systems require no subsequent separation of the catalyst, which allows their continuous operation. Crystalline and amorphous metal oxides based on titanium dioxide synthesized using the sol gel technique and containing catalytically active polymetallic nanoparticles are potentially the most stable coatings. The catalytic properties and operational stability of capillary microreactors are studied at atmospheric pressure and compared to those of conventional industrial batch reactors. Our Pd50Zn50/TiO2 coating displays higher activity (1.5 gMBE/(gPd s)) and selectivity (96.7%) than coatings described earlier, and retains high catalytic performance after 88 h of a reaction with Lindlar’s industrial catalyst.
      PubDate: 2021-10-01
       
  • Mononuclear Iron(III) Piperazine-Derived Complexes and Application in the
           Oxidation of Cyclohexane

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      Abstract: Oxygenated products from selective hydrocarbon oxidation have high commercial value as industrial feedstocks. One of the most important industrial processes is the cyclohexane oxidation to produce cyclohexanol and cyclohexanone. These organic substances have special importance in the Nylon manufacture as well as building blocks for a variety of commercially useful products. In this work we present the synthesis and characterization of a new mononuclear piperazine-derived series of iron(III) complexes and their catalytic activity towards cyclohexane oxidation essays. All complexes present octahedral high-spin iron(III) center according to elemental analysis, FTIR, UV-VIS and Mössbauer spectroscopy characterization. The cyclohexane oxidation resulted in cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide as products, with yields up to 39%. The best results were obtained with the complex (NH4)[Fe(BPPZ)Cl2] (BPPZ: lithium 1,4-bis(propanoate)piperazine) and with hydrogen peroxide as oxidant. The reactions were carried out at room temperature and atmospheric pressure, which incomes a great advantage over the current industrial process of cyclohexane production.
      PubDate: 2021-10-01
       
  • Nickel- and Molybdenum-Containing Catalysts for Direct Synthesis of
           Propylene from Ethylene: Effect of the Support

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      Abstract: Polyfunctional Ni- and Mo-containing catalysts are prepared by sequentially impregnating a support (SiO2, Al2O3, B2O3–Al2O3, \({\text{SO}}_{4}^{{2 - }}\) /Al2O3, \({\text{SO}}_{4}^{{2 - }}\) /ZrO2) using solutions of corresponding salts with intermediate steps of drying at 120°C and calcination at 500–550°C. X-ray powder diffraction, temperature programmed reduction, UV-VIS diffuse reflectance spectroscopy, and electron spin resonance spectroscopy are used to study physicochemical properties of the prepared catalysts. The catalysts are tested in the direct synthesis of propylene from ethylene at an atmospheric pressure, 200°C and an ethylene weight hourly space velocity of 0.5 h−1. The highest conversion of ethylene and yield of propylene are achieved for a sample based on borated alumina, due to the formation of active sites of ethylene dimerization, Ni2+ ions bound to acid sites of the support, and active sites of metathesis (surface monomolybdate compounds).
      PubDate: 2021-10-01
       
  • Use of Fluorinated Alumina as a Support for the Sulfated Zirconia Catalyst
           of Hexane Isomerization

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      Abstract: The effect of fluorine addition to the alumina matrix used for the preparation of supported sulfated zirconia catalysts has been studied. The fluorinating agent was hydrofluoric acid. Fluorine additions affect the textural characteristics of the Al2O3 matrix and, as a consequence, the surface area of sulfated zirconia catalysts based on modified systems. The introduction of fluorine in the catalyst composition to an increase in the activity (conversion of hexane) and yield of the high-octane isomer 2,2-dimethylbutane.
      PubDate: 2021-10-01
       
  • Study of Carbon Dioxide Hydrogenation to Hydrocarbons Over Iron-Based
           Catalysts: Synergistic Effect

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      Abstract: Hydrogenation of CO2 to CO and hydrocarbons is carried out over a wide range of catalysts. Group of VIIIB transition metals have proved high conversion and selectively for CO and methane. Meanwhile, low cost and effective catalysts are preferable in an industrial scale. In this work, the synergistic effect of iron content on the catalytic performance were investigated in carbon dioxide hydrogenation reaction. Incipient wetness impregnation procedure was used for the preparation of four γ-Al2O3 supported iron-based catalysts. BET, XRD, H2-TPR and TEM techniques were employed for the catalyst characterization. The evaluation of catalysts were carried out in a fixed bed reactor at the process conditions of temperature of 300°C, pressure of 20 atm, H2 to CO2 ratio of 3 and GHSV of 3 NL/(h gCat). It was found that the promoter addition improves the activity of Fe catalyst for both Fischer-Tropsch synthesis (FTS) and Reverse Water Gas Shift (RWGS) reactions. The results showed that conversion of CO2 was from 15.6 to 35.6% with major products of methane, C2 to C4, C5+ and CO. It was also found that impact of K and Ce promoters into iron catalyst showed the highest conversion and hydrocarbon yield due to the synergistic effect.
      PubDate: 2021-10-01
       
  • Oligomerization of Ethylene to Linear α-Olefins Using Complex Catalytic
           Systems of Zirconium Carboxylate

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      Abstract: The oligomerization of ethylene in aliphatic and aromatic solvents on complex zirconium carboxylate catalytic systems obtained from naphthenic acid fractions isolated from Baku oils is studied for the first time. Comparative studies are performed using complex zirconium carboxylate catalytic systems obtained from individual carboxylic acids CH3(CH2)2COOH and CH3(CH2)8COOH. It is found that the activity of a catalyst and the molecular weight distribution (MWD) of oligomeric products depend mainly on the solvent and the composition of the zirconium complex. It is shown that the rate of ethylene oligomerization when using zirconium carboxylate catalytic systems in aliphatic solvents is 2–3 times lower than in aromatic solvents. The resulting product has a narrow MWD and consists mainly of C4–C10 fractions. The oligomeric products obtained in aromatic solvents have wide MWDs and consist mainly of C4–C18 in the presence of zirconium carboxylates and of C12–C18 and C20 fractions with zirconium naphthenates.
      PubDate: 2021-10-01
       
  • Catalysts in the Direct Synthesis of Organotin Compounds, Part 2:
           Reactions between Alkyl Halides and Metallic Tin

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      Abstract: The second part of a series of reviews on the direct synthesis of organotin compounds is presented. In this part, the conditions and results of the reaction between metallic tin and allkyl halides are considered. The efficiency of application is analyzed for different catalysts along side with their systematization, and some possible mechanisms of these processes are discussed.
      PubDate: 2021-10-01
       
  • Effect of Tungsten Oxide Content in Pt/WO3-ZrO2 Catalysts on the
           Performance Characteristics of the Heptane–Benzene Mixture
           Hydroisomerization Reaction

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      Abstract: The effect of the tungsten oxide content (10–35 wt %) in Pt/WO3-ZrO2 catalysts on hydroisomerization of a heptane–benzene mixture (80 : 20, wt %) has been studied. The catalysts with 15–25 wt % WO3 are characterized by the highest fraction of the tetragonal phase of zirconia (t-ZrO2, 87–96%), which makes it possible to achieve the highest yield of the sum of heptane isomers, including high-octane di- and trimethyl-substituted isomers (DTMS; 69.4–76.7 and 24.5–27.9 wt %, respectively). In the presence of these catalysts, the yield of methylcyclopentane is 52.1–61.3 wt % at 72.6–90.9% selectivity of isomerization of cyclohexane to methylcyclopentane.
      PubDate: 2021-10-01
       
  • Effect of the Indium Introduction Method on the Properties of the
           Pt/In/Al2O3–Cl Reforming Catalysts

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      Abstract: The effect of 0.3 wt % of indium introduced at the peptization and aluminum oxide impregnation stages on the properties of alumina-platinum reforming catalysts has been studied. Modification with indium at the impregnation stage reduces the total acidity of the support to a lesser extent and, as a consequence, the conversion of heptane for the corresponding Pt/In/Al2O3-Cl catalyst. This sample demonstrates the greatest decrease in the selectivity of the hydrogenolysis and hydrocracking reaction alongside with a maximum ratio of i-C5–7/toluene selectivities as compared to the catalysis doped with In at the peptization stage and without doping.
      PubDate: 2021-10-01
       
  • Synthesis of Erythrulose from Dihydroxyacetone and Formaldehyde Using Zinc
           Zeolitic Imidazolate Frameworks

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      Abstract: A study is performed for the aldol condensation of formaldehyde with dihydroxyacetone (DHA) in an aqueous medium (pH 7.54–8.71) at 65–80°C using zinc zeolitic imidazolate frameworks based on 2-methylimidazole (ZIF-8) and 2-ethylimidazole (MAF-5 and MAF-6). It is shown that the selectivity of the process depends on the pH of the reaction solution, which is controlled by the temperature of the reaction and the amount of catalyst in the reaction mixture. There are high yields of C6 sugars when the reaction is conducted at pH 8.36 and 80°C. The sugars are accompanied by high yields of erythrulose (39–60%) at a temperature of 65°C and. It is found that the yield of erythrulose when using the studied catalytic systems depends on the pore radius and grows in the order MAF-6 > MAF-5 > ZIF-8. The advantages of the studied systems are compared to those of homogeneous and heterogeneous phosphate systems proposed in the literature.
      PubDate: 2021-10-01
       
  • Catalytic Properties and Chemical Stability of Potassium Polyferrites with
           Additives of Quadruply Charged Cations

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      Abstract: A study is performed of the effect of additives of quadruply charged ions on the composition, chemical stability, and catalytic properties of samples of potassium polyferrites with a β″-alumina type structure of \({{{\text{K}}}_{{\text{2}}}}{\text{Fe}}_{{{\text{1 + }}q}}^{{{\text{II}}}}{\text{Fe}}_{{{\text{10}} - {\text{2}}q}}^{{{\text{III}}}}{\text{Me}}_{q}^{{{\text{IV}}}}{{{\text{O}}}_{{{\text{17}}}}}\) , where Me is Ce, Ti, or Zr, and q = 0–1.0. The mechanism is determined for the effect produced by the additives of quadruply charged cations on the activity, selectivity, and corrosion resistance of β″-potassium polyferrite is determined. Polyferrites doped with quadruply charged cations are characterized by a drop in the specific rate of styrene formation and an increase in ethyl benzene dehydrogenation selectivity. The destabilizing effect of titanium additives is revealed. It is expressed in facilitating the emission of an alkali metal from the crystal lattice of polyferrite. Cerium additives result in the destruction of the polyferrite structure due to the reduction of Ce4+→ Be3+ for values of parameter q greater than 0.6. Zirconium additives do not reduce the corrosion resistance of ferrite systems under the conditions of dehydrogenation.
      PubDate: 2021-10-01
       
  • Conversions of Ethane and Ethylene with Methane on a Resistive Fechral
           Catalyst in the Presence of Hydrogen

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      Abstract: The conversion of methane–ethane, methane–ethylene, hydrogen–ethane, and hydrogen–ethylene mixtures on an electrically heated resistive fechral catalyst is studied. In the course of conversion, the catalyst surface is covered with graphite-like carbon deposits that have an additional catalytic effect resulting in the formation of C3 and C4 hydrocarbons. The latter are apparently formed with participation of ethylene formed from ethane. Hydrogen suppresses coking on the catalyst’s surface and reduces the yield of C3 and C4 hydrocarbons.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030090
       
  • Modeling the Synthesis of Nitrous Oxide in a Microchannel Reactor: Effect
           of Parameters on Temperature Regimes and Capacity

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      Abstract: A study on the synthesis of nitrous oxide via the selective oxidation of ammonia in a microreactor in the form of a metallic disk with cylindrical channels filled with a manganese–bismuth oxide catalyst has been. A 3D mathematical model is presented for this microreactor that considers the transfer of mass and axial and radial heat, the catalytic reactions, the change they produce in the volume of the reaction mixture, the transfer of heat between the disk and the channels, and the heat conductivity of the disk. Parameters are determined that ensure the maximum nitrous oxide production with allowance for the limitations of temperature in the microreactor channels. The highest efficiency of nitrous oxide production is attained at an outer reactor edge temperature of 370°C and an inlet ammonia concentration of 20 vol %. The production capacity per unit catalyst volume in the microreactor is nearly 1.5 times higher than in a tubular reactor, and the maximum temperature corresponds to the level that provides the best process selectivity toward nitrous oxide.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030065
       
  • Effect of Treatment with Sodium Carbonate and Hydrogen on the Activity and
           Selectivity of Pd-Containing Polymer Catalysts for the Hydrogenation of
           Acetylene Compounds

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      Abstract: The catalytic hydrogenation of a carbon–carbon triple bond in acetylene compounds is an important industrial process in which high selectivity toward olefin compounds must be ensured. This work considers the effect of treating palladium catalysts based on hyper-cross-linked polystyrene (HPS) with sodium carbonate on the activity and selectivity in the hydrogenation of 2-methyl-3-butyn-2-ol and phenylacetylene is considered. The effect of such treatment depends on the palladium precursor and the polymer support (HPS non-functionalized or HPS containing tertiary amino groups). Selectivity in the hydrogenation of 2-methyl-3-butyn-2-ol (95% conversion of the substrate) is 98% at ambient hydrogen pressure and 90°C in toluene for 1%-Pd/HPS catalysts treated with Na2CO3 and 99.5% in the hydrogenation of phenylacetylene.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030028
       
  • Catalysts for the Direct Synthesis of Organotin Compounds, Part 1:
           Reactions between Organohalides and Tin Alloys

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      Abstract: This review is the first part of a series of reviews devoted to the direct synthesis of organotin compounds. The conditions for and results from the reaction between tin alloys and organohalides are considered. The efficiency of catalysts and the prospects for using tin alloys in the synthesis of organotin compounds are analyzed, and some possible mechanisms of these processes are discussed.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030107
       
  • Effect of Carbon Monoxide on the Oxidation of Propane on Pt Glass Fiber
           Catalyst

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      Abstract: The deep oxidation of hydrocarbons on platinum catalysts underlies most processes for cleaning gas emissions from industrial enterprises. Since carbon monoxide is usually present in exhaust gases, it is important to study its effect on the kinetics of hydrocarbon oxidation. This work presents results from studying the kinetics of propane oxidation on a platinum glass fiber catalyst with and without CO in the reaction mixture. It is found that CO strongly inhibits the oxidation of propane at low temperatures. The effect of CO changes from negative to positive as the temperature rises. Numerical modeling shows the multidirectionality of the effect can be explained by competition between the adsorption of oxygen, propane, and CO on the active sites of the catalyst.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030077
       
  • γ-Valerolactone as a Promising Solvent and Basic Chemical Product:
           Catalytic Synthesis from Plant Biomass Components

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      Abstract: γ-Valerolactone (GVL) is a valuable chemical compound known as a platform molecule. It is considered as an intermediate product for the synthesis of chemical compounds with high added value, components of motor fuels, and biopolymers. GVL is well established as an environmentally safe solvent, fuel additive, flavoring, and nutritional supplement. This review summarizes the latest advances in the development of catalytic ways of GVL synthesis from levulinic acid (LA), alkyl levulinates (ALs), and carbohydrates and plant polymers. Special attention is given to heterogeneous catalysts based on metals and metal oxides, which are more promising for practical application. Proposed mechanisms of the processes are considered in detail, and the prospect of using hydrogen-donor solvents in the processes of GVL production is discussed. Catalysts demonstrating the best catalytic properties are compared from the viewpoint of their productivity, an important parameter for industrial catalysis.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030119
       
  • Thermocatalytic Decomposition of Methane on Carbon Materials and Its Use
           in Hydrogen Energy Technologies

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      Abstract: It is important today to find ways for the synthesis of hydrogen such as to avoid emissions of carbon oxides into the atmosphere and ensure the use of so-called low-carbon energy. Producing hydrogen through the thermocatalytic methane decomposition (CMD) on carbon catalysts yields not only a valuable, environmentally friendly fuel in the form of hydrogen, but also a wide range of carbon materials that can be used in a number of industries. The use of carbon catalysts is essential for the economic efficiency of methane decomposition. This paper describes the CMD fundamentals and summarizes results from studying the catalytic activity in this process for carbon materials (activated carbon, carbon black, nanotubes, nanofibers) that differ in structure and physical and chemical properties. The main problems and prospects of using this technology are identified.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030089
       
  • Features of the Liquid-Phase Oxidation of Alkenes to Carbonyl Compounds in
           the Presence of Palladium Compounds

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      Abstract: Some specific features in the liquid-phase oxidation of alkenes to ketones or aldehydes in the presence of palladium compounds (Wacker oxidation) are discussed. It is shown that selecting the appropriate conditions of the reaction (the effective compositions of the catalyst, the oxidizing agent, and solvent) allows the selective synthesis of either ketones or aldehydes from terminal alkenes and ketones from internal alkenes.
      PubDate: 2021-07-01
      DOI: 10.1134/S2070050421030041
       
 
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