Subjects -> CHEMISTRY (Total: 928 journals)     - ANALYTICAL CHEMISTRY (59 journals)    - CHEMISTRY (661 journals)    - CRYSTALLOGRAPHY (23 journals)    - ELECTROCHEMISTRY (28 journals)    - INORGANIC CHEMISTRY (45 journals)    - ORGANIC CHEMISTRY (47 journals)    - PHYSICAL CHEMISTRY (65 journals) CHEMISTRY (661 journals)            First | 1 2 3 4 | Last
 Showing 401 - 600 of 735 Journals sorted alphabetically Journal of Molecular Liquids       (Followers: 3) Journal of Molecular Modeling       (Followers: 5) Journal of Molecular Recognition       (Followers: 2) Journal of Molecular Spectroscopy       (Followers: 6) Journal of Molecular Structure       (Followers: 6) Journal of Nanoparticles       (Followers: 4) Journal of Nanostructure in Chemistry       (Followers: 8) Journal of Organometallic Chemistry       (Followers: 25) Journal of Photochemistry and Photobiology Journal of Photochemistry and Photobiology A: Chemistry       (Followers: 3) Journal of Photochemistry and Photobiology B: Biology       (Followers: 4) Journal of Photochemistry and Photobiology C: Photochemistry Reviews       (Followers: 3) Journal of Polymer & Composites       (Followers: 17) Journal of Polymer and Biopolymer Physics Chemistry       (Followers: 7) Journal of Polymer Science Part A: Polymer Chemistry       (Followers: 92) Journal of Polymers       (Followers: 7) Journal of Porphyrins and Phthalocyanines       (Followers: 1) Journal of Progressive Research in Chemistry Journal of Pure and Applied Chemistry Research       (Followers: 3) Journal of Raman Spectroscopy       (Followers: 14) Journal of Research and Education Chemistry       (Followers: 1) Journal of Research Updates in Polymer Science       (Followers: 2) Journal of Rubber Research       (Followers: 1) Journal of Saudi Chemical Society Journal of Solid State Chemistry       (Followers: 13) Journal of Solution Chemistry       (Followers: 1) Journal of Structural Chemistry       (Followers: 1) Journal of Sulfur Chemistry       (Followers: 1) Journal of Supercritical Fluids       (Followers: 3) Journal of Superhard Materials Journal of Surface Science and Technology Journal of Surfactants and Detergents       (Followers: 3) Journal of Taibah University for Science Journal of the American Chemical Society       (Followers: 323) Journal of the American Society for Mass Spectrometry       (Followers: 32) Journal of the American Society of Brewing Chemists       (Followers: 2) Journal of the Chilean Chemical Society       (Followers: 2) Journal of the Chinese Chemical Society Journal of the Indian Chemical Society Journal of The Indonesian Society of Integrated Chemistry Journal of the Iranian Chemical Society       (Followers: 1) Journal of the Korean Society for Applied Biological Chemistry Journal of the Mexican Chemical Society       (Followers: 1) Journal of the Serbian Chemical Society Journal of the Turkish Chemical Society, Section A : Chemistry Journal of Theoretical and Computational Chemistry       (Followers: 9) Jurnal Inovasi Pendidikan Kimia Jurnal Kimia (Journal of Chemistry) Jurnal Kimia Riset Jurnal Pendidikan Kimia Jurnal Penelitian Sains (JPS) Karbala International Journal of Modern Science Kinetics and Catalysis       (Followers: 4) Konfigurasi : Jurnal Pendidikan Kimia dan Terapan Korea-Australia Rheology Journal       (Followers: 1) Langmuir       (Followers: 58) Lebensmittelchemie       (Followers: 1) Lipid Insights Luminescence       (Followers: 2) Macromolecular Materials & Engineering       (Followers: 5) Macromolecular Rapid Communications       (Followers: 10) Macromolecular Research       (Followers: 2) Macromolecular Symposia       (Followers: 3) Macromolecular Theory and Simulations       (Followers: 2) Macromolecules       (Followers: 48) Magnetic Resonance in Chemistry       (Followers: 8) Magnetochemistry Marine Chemistry       (Followers: 6) Marine Drugs       (Followers: 1) MATEC Web of Conferences Materials Advances       (Followers: 2) Materials and Devices Materials Characterization       (Followers: 32) Materials Chemistry Frontiers       (Followers: 4) Materials Horizons       (Followers: 6) Materials Research Bulletin       (Followers: 25) Materials Science-Poland       (Followers: 1) Materials Sciences and Applications       (Followers: 2) Medicinal Chemistry Research       (Followers: 9) Mediterranean Journal of Chemistry Metallography, Microstructure, and Analysis       (Followers: 1) Micro and Nano Systems Letters       (Followers: 6) Microchimica Acta       (Followers: 2) Microporous and Mesoporous Materials       (Followers: 9) Modern Chemistry & Applications       (Followers: 1) Modern Research in Catalysis Molbank Molecular Catalysis       (Followers: 6) Molecules       (Followers: 4) Molecules and Cells       (Followers: 1) Monatshefte für Chemie - Chemical Monthly       (Followers: 4) Mongolian Journal of Chemistry Moscow University Chemistry Bulletin       (Followers: 1) MRS Bulletin       (Followers: 4) Nachrichten aus der Chemie       (Followers: 18) Nano Convergence       (Followers: 1) Nano Materials Science       (Followers: 1) Nano Reviews & Experiments       (Followers: 14) Nano Select Nanochemistry Research       (Followers: 1) Nanoscale       (Followers: 18) Nanoscale Advances Nanoscale Horizons Nanoscale Research Letters       (Followers: 8) Nanoscience and Nanotechnology Letters       (Followers: 24) Natural Product Communications Natural Product Reports       (Followers: 10) Natural Science       (Followers: 8) Natural Volatiles & Essential Oils Nature Chemistry       (Followers: 97) Nature Protocols       (Followers: 72) Nature Reviews Chemistry       (Followers: 17) New Journal of Chemistry       (Followers: 17) Nitric Oxide Nitrogen Nukleonika Open Chemistry Journal Open Conference Proceedings Journal Open Journal of Chemistry Open Journal of Composite Materials       (Followers: 22) Open Journal of Inorganic Non-metallic Materials       (Followers: 2) Open Journal of Medicinal Chemistry       (Followers: 4) Open Journal of Polymer Chemistry       (Followers: 12) Open Journal of Synthesis Theory and Applications Open Medicinal Chemistry Journal Orbital - The Electronic Journal of Chemistry       (Followers: 1) Organic & Biomolecular Chemistry       (Followers: 57) Organometallics       (Followers: 19) Oxidation of Metals       (Followers: 16) Passer Journal of Basic and Applied Sciences Peptide Science Pharmaceuticals       (Followers: 4) Pharmaceutics       (Followers: 5) Phosphorus, Sulfur, and Silicon and the Related Elements       (Followers: 2) Photochemistry and Photobiology       (Followers: 3) Physical Science International Journal Physics and Materials Chemistry       (Followers: 1) Phytochemistry       (Followers: 4) Phytochemistry Letters       (Followers: 1) Plasma       (Followers: 3) Plasma Chemistry and Plasma Processing       (Followers: 3) Polycyclic Aromatic Compounds Polyhedron       (Followers: 4) Polymer Chemistry       (Followers: 24) Polymer crystallization Polymer Degradation and Stability       (Followers: 23) Polymer Engineering & Science       (Followers: 14) Polymer Reviews       (Followers: 32) Polymer Science Series D       (Followers: 3) Polymer Testing       (Followers: 193) Polymer-Plastics Technology and Materials       (Followers: 5) Polymers       (Followers: 21) Polymers from Renewable Resources Proceedings of the Combustion Institute       (Followers: 8) Processes Progress in Lipid Research       (Followers: 3) Progress in Organic Coatings       (Followers: 7) Progress in Polymer Science       (Followers: 36) Progress in Reaction Kinetics and Mechanism Progress in Solid State Chemistry       (Followers: 3) Progress in Surface Science       (Followers: 3) Protein Science       (Followers: 45) Radiochemistry       (Followers: 1) Rapid Communications in Mass Spectrometry       (Followers: 33) Reaction Chemistry & Engineering Reaction Kinetics, Mechanisms and Catalysis       (Followers: 3) Reactions Reportes Científicos de la FaCEN Research Journal of Phytochemistry       (Followers: 1) Resources Chemicals and Materials       (Followers: 2) Results in Chemistry Results in Geochemistry Results in Surfaces and Interfaces Review Journal of Chemistry       (Followers: 1) Reviews in Mineralogy and Geochemistry       (Followers: 4) Revista Boliviana de Química Revista CENIC. Ciencias Quimicas Revista Colombiana de Ciencias Químico-Farmacéuticas Revista Colombiana de Química Revista Cubana de Química Revista de Ciencia y Tecnología Revista de Ciencias Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales Revista de la Sociedad Química del Perú Revista de la Societat Catalana de Química Revista de Química       (Followers: 3) Revista Debates em Ensino de Química Revista ION RSC Advances       (Followers: 27) RSC Chemical Biology RSC Medicinal Chemistry       (Followers: 6) Russian Journal of Bioorganic Chemistry       (Followers: 1) Russian Journal of Coordination Chemistry       (Followers: 1) Russian Journal of General Chemistry       (Followers: 1) Russian Journal of Inorganic Chemistry Sainstek : Jurnal Sains dan Teknologi Science China Chemistry       (Followers: 2) Science Talks       (Followers: 2) Sciences & Technologie A : sciences exactes Scientific Journal of Frontier Chemical Development       (Followers: 2)

First | 1 2 3 4 | Last

Similar Journals
 Kinetics and CatalysisJournal Prestige (SJR): 0.262 Citation Impact (citeScore): 1Number of Followers: 4      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1608-3210 - ISSN (Online) 0023-1584 Published by Springer-Verlag  [2469 journals]
• Specific Features of the Liquid-Phase Hydrogenation of 2-Butyne-1,4-Diol
under the Action of Palladium–Phosphorus Particles

Abstract: Efficient catalyst systems based on Pd–P particles for the chemoselective hydrogenation of 2‑butyne-1,4-diol, which are superior to Ziegler-type systems in turnover frequency under mild conditions, have been proposed. The introduction of phosphorus into the composition of palladium nanoparticles makes it possible to maintain a nearly 100% 2-butene-1,4-diol selectivity up to a 90% alkynediol conversion and affects the ratio between the hydrogenation rates of the triple and double bonds of alkynediol. Poly(N-vinylpyrrolidone) increases the aggregative stability of Pd–P particles during their functioning; however, it has hardly any effect on the activity and selectivity in 2-butyne-1,4-diol hydrogenation.
PubDate: 2022-04-01

• Effect of Salt and Phosphine Additives on the Composition of Active
Palladium Complexes in the Mizoroki–Heck Reaction with Aromatic
Carboxylic Anhydrides

Abstract: This paper presents the results of studies on changes in the composition of palladium complexes responsible for the activation of substrates in the Mizoroki–Heck reaction between aromatic acid anhydrides and alkenes. The differential selectivity of the reaction under conditions of competition between a pair of anhydrides or alkenes indicates the catalytic activity of palladium complexes, the composition of which varies depending on the concentration ratio of a tertiary phosphine, an alkali metal halide used as a promoting additive, and a palladium catalyst precursor loaded into the system. It was found that, when the threshold values of the concentrations ratio between halide ions and the tertiary phosphine were achieved, only phosphine-free palladium complexes containing halide anions in their coordination sphere made a decisive contribution to the formation of reaction products in spite of the presence of phosphine in the system. At the same time, when a halide salt was present in low concentrations or absent at all, active Pd complexes could include tertiary phosphine (in phosphine-containing catalytic systems) and solvent molecules and aromatic carboxylate anions formed as a result of the conversion of the initial anhydride. Under the “noncompetitive” conditions of the Mizoroki–Heck reaction, it was found that the nature of the cation and anion of a halide salt added to the catalytic system had a key effect on the differential selectivity of the formation of a classical “Heck” product of alkene arylation and a carbonyl product (chalcone) formed through the parallel reaction pathway. It was demonstrated that the differential selectivity and the yield of the carbonyl-containing reaction product increased when bromide salt additives were used. Therefore, in principle, it is possible to control the composition of active palladium complexes responsible for the selective formation of various products in the Mizoroki–Heck reaction with aromatic acid anhydrides.
PubDate: 2022-04-01

• Kinetic Model and Mechanism of Hydrogenation of Unsaturated Carbocyclic

Abstract: Liquid-phase hydrogenation of bicyclo[2.2.1]hepta-2,5-diene (norbornadiene, ND) proceeds in the presence of an industrial palladium catalyst Pd/γ-Al2O3 (PK-25) in an n-heptane solution at 76°C via consecutive formation of bicyclo[2.2.1]hept-2-ene (norbornene, NE) and bicyclo[2.2.1]heptane (norbornane, NA), as well as tricyclo[2.2.1.02,6]heptane (nortricyclane, NT) as a minor product. The reaction products were identified, the main routes were determined, and the material balance was studied. Preferable adsorption of ND at the active palladium site over adsorption of other components of the system was confirmed. A parallel-serial scheme of the process mechanism was proposed based on the sum of experimental and theoretical data. Zero order kinetics was observed in a wide range of initial substrate concentrations. The apparent rate constants of each stage were measured. A detailed kinetic model was developed based on the Langmuir–Hinshelwood approach, assuming multiple adsorption of substrates at a single active site of the heterogeneous catalyst. The model adequately describes the available experimental data using the proposed mechanism of ND hydrogenation. The possibility of a “cocktail” mechanism for the given reaction was discussed.
PubDate: 2022-04-01

• Catalytic Ozonation of Oxalic Acid in Aqueous Solution in the Presence of
Manganese Ions

Abstract: The kinetics of mineralization of oxalic acid Н2С2О4 under the action of ozone in acidic aqueous solution (С(НClО4) = 0.1 M, pH ~ 1) with the addition of $${\text{MnO}}_{4}^{ - }$$ or Mn2+ ions was studied. It was found that manganese ions are effective catalysts for the reaction of O3 with oxalic acid. Regardless of the manganese species ( $${\text{MnO}}_{4}^{ - }$$ or Mn2+) added to the solution, it was converted into an oxalate complex of tetravalent manganese in the course of the reaction, and this complex was the stable form of the catalyst in the system under consideration. The kinetics of release of carbon dioxide—a product of the reaction of Н2С2О4 with О3—was determined depending on the concentrations of ozone in the gas stream and oxalic acid and manganese in the solution. A basic scheme of the catalysis of the test reaction by manganese ions was proposed, and a kinetic model was constructed to adequately describe the experimental results. The reaction scheme is based on the fact that oxalate is oxidized to CO2 in the course of a complex decomposition reaction of the oxalate complex of tetravalent manganese; in this case, Mn(IV) is reduced to Mn2+. The complex is regenerated by the oxidation of Mn2+ to Mn(IV) with ozone.
PubDate: 2022-04-01

• Production of Alcohols and Olefins from CO and H2 on a Cobalt Catalyst at
High Pressures and in the Gas Circulation Mode

Abstract: The results of a study of the synthesis of products from CO and H2 on a supported industrial Co–Al2O3/SiO2 catalyst under medium and high pressures in the gas circulation mode are presented. It was found that an increase in pressure from 2.0 to 8.0 MPa led to an increase in the amount of formed alcohols and synthesis olefins by factors of 10.5 and 2.0, respectively. It was determined that alcohols obtained in the synthesis were not the products of olefin hydration. The effect of an increase in selectivity for C5+ products with temperature at a high pressure in the gas recirculation mode, which is atypical for the Fischer–Tropsch synthesis, was confirmed.
PubDate: 2022-04-01

• On the Influence of Ionic Strength on the Kinetics of Sulfite Oxidation in
the Presence of Mn(II)

Abstract: The paper considers available published data on the effect of the ionic strength of solutions on the kinetics of oxygen oxidation of sulfite in acidic solutions (pH 1.3–4.5) in the presence of manganese(II) ions. It was found that a consistent picture of this effect arises when the process is considered within the framework of a degenerate-branched chain mechanism with the participation of trace iron ions as an initiator. This approach, in agreement with the experimental data, led to the identification of two different modes of this process and made it possible to obtain explicit expressions for the observed reaction rate constants. This paper presents new expressions to describe the negative effect of ionic strength (~10–3–1.5 M) on the reaction rate constants in both modes.
PubDate: 2022-04-01

• Methyl Acetate Synthesis by Dimethyl Ether Carbonylation in the Presence
of Zeolites: A Review

Abstract: The review analyzes the specific features of methyl acetate synthesis by dimethyl ether carbonylation in the presence of zeolite catalysts. The structural characteristics of zeolites, in particular, mordenite and ferrierite, that affect carbonylation are discussed. The bridging hydroxyl groups (Al–OH–Si) of zeolites function as Brønsted acid sites and interact with dimethyl ether. The carbonylation reaction is characterized by an induction period, during which dimethyl ether molecules interact with Brønsted acid sites to form methoxy groups. The incorporation of CO into the methoxy group leads to the formation of an acetyl intermediate. Methyl acetate is formed due to the interaction between a dimethyl ether molecule and an acetyl intermediate. The reaction is facilitated by the confinement effect characteristic of small zeolite pores, in particular, eight-membered pockets of mordenite. Methyl acetate is synthesized at moderate temperatures (about 200°C) in a CO–dimethyl ether mixture at a high selectivity and a significant dimethyl ether conversion. The occurrence of hydrocarbon formation side reactions, along with the methyl acetate synthesis target reaction, is observed; the side reactions decrease the on-stream stability of the catalyst. In the case of mordenite, these reactions are attributed to the sites present in the twelve-membered channels. The on-stream stability of the catalysts can be increased by using special techniques for neutralizing the deactivating sites of the zeolite. The effect can be achieved by pyridine adsorption or ion exchange of the respective protons of the mordenite structure for organic or metal cations. The introduction of zinc ions and, additionally, copper ions significantly inhibits the activity of the mordenite sites on which the side reactions occur. A new area of research is the use of multifunctional catalysts that mediate methyl acetate synthesis directly from synthesis gas.
PubDate: 2022-04-01

• Estimation of the Integral Toxicity of Photocatalysts Based on Graphitic
Carbon Nitride in a Luminescent Test

Abstract: A ternary heterosystem consisting of crystalline graphitic carbon nitride, zinc oxide, and zinc sulfide (g-C3N4/ZnO/ZnS) was obtained by the one-stage decomposition of a mixture of thiourea and zinc acetate. The integral toxicity index of the resulting material was estimated in a luminescent test with a genetically modified Escherichia coli strain as a test object. The effect of quenching the luminescence of E. coli was noted both under exposure to UV radiation due to photocatalytic reactions on the surface of g-C3N4/ZnO/ZnS leading to the formation of highly oxidative radical ions interacting with cell membranes and without irradiation due to mechanical interactions with bacterial cells. At a 0.3 g/L concentration of g-C3N4/ZnO/ZnS in aqueous solution, the toxicity index T reached 75.6% under UV irradiation. In this case, an increase in the toxicity index T of the ternary heterosystem in a test concentration range from 0.1 to 0.3 g/L was 6 or 10–11% under UV radiation or without illumination, respectively, as compared with that of the pure graphite-like carbon nitride obtained under identical conditions.
PubDate: 2022-04-01

• Comparison of the Activities of Pd(0) and Pd(I) in Low-Temperature
Oxidation of Carbon Monoxide on the Pd/γ-Al2O3 Catalyst

Abstract: Low-temperature oxidation of carbon monoxide on the Pd/γ-Al2O3 catalyst has been studied at room temperature and atmospheric pressure of air containing 100 mg/m3 CO. The catalyst became gradually deactivated during the process. Storage of the partially deactivated catalyst in air for 10–12 h resulted in a complete recovery of activity. According to XPS data, the material obtained by depositing Pd3(OAc)6 on γ-Al2O3 before contact with CO contains palladium compounds in the oxidation states I and 0. The specific catalytic activity of palladium compounds in different oxidation states was evaluated based on the correlation between the catalytic activity and the content of Pd(I) and Pd(0) compounds, and it was shown that the activity of the former is higher than that of the latter.
PubDate: 2022-04-01

• para-Substituent Effect on the Decay Kinetics of the Isomeric Forms of
Aromatic Nitroso Oxides

Abstract: Flash photolysis of aromatic azides 4-R–C6H4N3 (where R = Ph, OPh, CH2Ph) in aerated acetonitrile solutions led to the intermediate formation of cis and trans isomers of the corresponding aryl nitroso oxides, which then presumably transformed via the aromatic ring opening into R-substituted unsaturated nitrile oxides. The electronic spectra of the cis and trans isomers of 4-R–C6H4NOO were recorded; the effective rate constants of the monomolecular decay of the isomers were determined, and the activation parameters of the rate constants were found. The rate constants ktrans are significantly lower than kcis, slightly varying in the series of nitroso oxides in the range 0.15–0.22 s–1 (295 K). The rate constants kcis for phenyl- (2.5 s–1) and benzyl- (2.8 s–1) substituted aryl nitroso oxides coincide within the experimental error, whereas the phenoxy substituent leads to an increase in kcis by a factor of ~1.5 (4.3 s–1). The decay of 4-R–C6H4NOO is represented by a system of three elementary reactions, including reversible isomerization of the cis and trans isomers and ortho-cyclization of cis-nitroso oxides into the corresponding nitrile oxide. Solving the system of differential equations describing the decay kinetics of 4-R–C6H4NOO led to an analytical time dependence of optical density of the reaction mixture, which coincides with the empirical dependence found earlier. This made it possible to reveal the physical meaning of the effective rate constants and calculate the elementary rate constants of the decay of aromatic nitroso oxides. The DFT calculations of activation barriers for cis-trans isomerization and irreversible ortho-cyclization of cis-4-R–C6H4NOO are in good agreement with experiment.
PubDate: 2022-04-01

• Biocatalytic Heterogeneous Processes of Low-Temperature Synthesis of Diol
Monoesters

Abstract: A study was made of the low-temperature synthesis of esters of heptanoic (enanthic, C7:0) acid and various diols using heterogeneous biocatalysts prepared by the adsorptive immobilization of the recombinant lipase rPichia/lip on macroporous carbon aerogel. The substrates were diols differing in length of the carbon skeleton (2 to 6 C atoms), position of the OH group, and isomerism of the carbon skeleton, namely, 1,2-ethanediol (ethylene glycol) and its oligomers (dimers and trimers), 1,2-propanediol (propylene glycol), 1,3‑propanediol, 1,4-butanediol, 1,6-hexanediol, and 2-ethyl-1,3-hexanediol. The esterification and synthesis of monoesters of heptanoic acid were carried out in batch reactors under very mild conditions (20 ± 2°C, 1 bar). The properties of the prepared biocatalysts, such as enzymatic activity, substrate specificity, and operational stability, were investigated depending on the structure of the diol molecule and the nature of the organic solvent (chloroform, hexane, acetone). It was found that C2–C4 short-chain diols irreversibly inhibited the immobilized lipase, and the biocatalyst was completely inactivated within 1–3 reaction cycles. The maximum activity (83 U/g) and the conversion of acid (94% in 24 h) were observed in the esterification of heptanoic acid with 1,6-hexanediol; under the studied conditions, the fraction of monoester was more than 99%. A correlation was found between the biocatalytic activity and the molecular length of symmetric diols: the esterification reaction rate increased with increasing distance between the terminal OH groups. Because chloroform inactivated the adsorbed rPichia/lip, the conditions for the reactivation of the biocatalysts were selected by replacing the reaction medium: the solvent by hexane and the diol by butanol.
PubDate: 2022-04-01

• Experimental Studies and Simulation of Methane Pyrolysis and Oxidation in
Reflected Shock Waves Accompanied by Soot Formation

Abstract: An experimental and computational study of methane pyrolysis and oxidation and formation of soot particles in reflected shock waves has been performed using a previously proposed unified kinetic model. The model makes it possible to describe the consumption of initial methane molecules and formation of products during pyrolysis and oxidation of various methane–oxygen–argon mixtures. The results of experiments in shock tubes of various designs, equipped with different means of detection of the initial components and secondary products, were compared with the predictions of kinetic simulations. In general, the kinetic model demonstrated good predictive power.
PubDate: 2022-04-01

• In Memoriam: R. A. Buyanov—A Scientometric View

Abstract: A bibliometric and subject analysis of more than 800 scientific publications (including ~90 patents and Inventor’s Certificates) of Corresponding Member of the RAS Roman Alekseevich Buyanov (1927–2020), one of the founders of the Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia, was performed using the Institute’s SciAct CRIS system and the Chemical Plus, Web of Science, Scopus, and Russian Science Citation Index databases. Buyanov’s main scientific activities were discussed, and his most cited works were identified.
PubDate: 2022-02-01

• Nonlinear Phenomena during CO Oxidation over Nickel

Abstract: The paper is devoted to the experimental and theoretical studies of self-sustained oscillations and wave phenomena during CO oxidation on Ni foil. A new type of spatial structures arising due to the redox processes of the catalyst and observed under isothermal conditions at atmospheric pressure were studied. A 3D distributed mathematical model was constructed, which describes the color change and the propagation of kinetic waves of nickel oxidation–reduction in a flow-through reactor. The main reason for the wave phenomena and their propagation during CO oxidation on nickel was shown to be the presence of an oxygen concentration gradient in the flow-through reactor due to the effect of mass transfer on the reaction rate.
PubDate: 2022-02-01

• Nickel as a Promising Electrocatalytic Material for Electrooxidation of
Hydrogen and Borohydride: State-of-the-Art and Future Challenges

Abstract: Nickel is widely used in heterogeneous catalysis of hydrogenation, reforming, methanation, and other processes. Utilization of nickel in heterogeneous electrocatalysis is less wide-spread, but has evidenced considerable growth in last decades. Herewith we present a brief review of Ni-based electrocatalysts for electrooxidation of hydrogen and borohydride with a special emphasis on electrode materials comprising metallic nickel—nickel oxide (hydroxide) heterostructures.
PubDate: 2022-02-01

• Technology for Producing Hydrogen and Carbon Nanofibers from Natural Gas

Abstract: A technology for producing hydrogen and carbon nanofibers from natural gas is considered. A catalyst that actively and stably operated at temperatures of 700–750°C was developed to achieve high conversions of methane. The genesis of its phase composition was investigated using electron microscopy and X-ray diffraction analysis. The modification of a 75%Ni–12%Cu/Al2O3 catalyst with iron oxide led to the formation of a ternary Ni–Cu–Fe alloy. The method developed for producing hydrogen effectively worked with the use of not only methane but also natural gas as a feedstock. An installation with a rotating reactor for producing hydrogen and carbon nanofibers from natural gas made it possible to carry out the process on a 70%Ni–10%Cu–10%Fe/Al2O3 catalyst for 20–30 h. The hydrogen concentration at the reactor outlet was higher than 70 mol %. The yield of hydrogen reached 590 L per gram of the catalyst.
PubDate: 2022-02-01

• Coking of Catalysts: Mechanisms, Models, and Influence

Abstract: This review considers the mechanism of multilayered coke formation on catalysts of various types and analyzes its possible variants. A detailed derivation of equations of the dynamics of accumulation for different types of coke and the kinetics of its deactivating effect is given. The substantiated dependences of the relative activity of a catalyst on the concentration of coke are derived. Specific examples of these dependences are presented. They confirm the advantages of rigorous models based on the mechanism of the phenomenon in comparison with the formal description of experiments, which does not have predictive power.
PubDate: 2022-02-01

• Synthesis and Structure of a New Ruthenium(II) Clathrochelate and the Use
of a Highly Porous Ceramic Material with an Immobilized Complex in the
Oxidative Conversion of Methane

Abstract: A new ruthenium(II) cage complex with polar terminal groups in the apical substituents has been synthesized; the molecular design of the complex contributes to the effective immobilization of it due to the adsorption on the surface of a heat-resistant highly porous silicate fibrous material used as a support. The complex has been synthesized by the template condensation of cyclohexanedione-1,2-dioxime (nioxime) and 4-(hydroxymethyl)phenylboronic acid on the ruthenium(II) ion using a [Ru(CH3CN)3(COD)Cl](BF4) solvatocomplex as a source of Ru2+ cations. The composition and structure of the synthesized macrobicyclic compound have been determined using data of elemental analysis, MALDI-TOF mass spectrometry, 1H and 13C{1H} NMR spectroscopy, and X-ray diffraction analysis. It has been shown that the synthesized hybrid material with immobilized ruthenium clathrochelate catalyzes the dry reforming of methane. The productivity of the catalyst system at 900°C achieves 9437 mol CO and 11797 mol H2 per gram-atom of ruthenium per hour.
PubDate: 2022-02-01

• A Study of the Electrochemical Characteristics of Single-Chamber Solid
Oxide Fuel Cells Based on Platinum and Strontium-Doped Lanthanum Manganite
Electrodes and Fed with a Methane–Air Mixture

Abstract: The properties of single-chamber solid oxide fuel cells (SC SOFCs) composed of an electrolyte based on yttria-stabilized zirconia (YSZ), a platinum anode, and a strontium-doped lanthanum manganite (LSM) cathode and fed with a methane–air mixture in a temperature range of 500–750°C have been studied. It has been shown that, in the presence of LSM, the methane conversion in the oxidation reaction at 650°C does not exceed 10%; therefore, LSM can be used as a cathode material in SC SOFCs. It has been shown that a Pt YSZ LSM cell makes it possible to generate electricity. The maximum specific power (36 mW/cm2), voltage (0.85 V), and short-circuit current density (132 mA/cm2) are achieved at 700°C, a [CH4]/[O2] ratio of ~1.0, and a reaction mixture feed rate of 330 cm3/min. The study has shown that it is possible to design SC SOFCs fed with a methane–air mixture, which are capable of generating electrical power. The methane remaining after the operation of SC SOFCs can be used to generate heat or converted to synthesis gas, which is used as a feedstock, for example, in the production of ammonia, methanol, or hydrocarbons by the Fischer–Tropsch process.
PubDate: 2022-02-01

• Comparative Analysis of the Dehydrogenation of Hydrocarbons and Alcohols
in a Membrane Reactor

Abstract: Membrane technologies are widely used in various modern technological processes. In the chemical industry, membranes are used to solve several problems from increasing the efficiency of targeted processes to ensuring strict environmental legislation. A special synergistic effect is expected in the field of membrane catalysis when it becomes possible not only to accelerate the main reaction using a catalyst affecting the kinetics of the process but also shift the reaction equilibrium toward the products due to the membrane separation of one or more products from the main reaction volume. This advantage of membrane catalytic technologies is especially in demand for endothermic processes. This mini review is devoted to the dehydrogenation of hydrocarbons exemplified by the production of the high demand monomers ethylene, propylene, and styrene and the dehydrogenation of alcohols exemplified by methanol as a key compound of the C1 chemistry.
PubDate: 2022-02-01

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762