Adsorption and Photocatalytic Activity of the Porous Glass–ZnO–Ag Composite and ZnO–Ag Nanopowder

Glass Physics and Chemistry - This article presents the results of a study of the effect on the adsorption properties of microporous glass of its modification with ZnO–Ag nanocrystals. The...     

Study on the Degradation Performance of 2,4-DCP by Modified Co–Ni–Fe Hydrotalcite

Catalysis Letters - In this study, chitosan-based Co–Ni-Fe layered double hydroxide (C-LDH) and Co–Ni-Fe layered double hydroxide (LDH) were prepared by low saturation co-precipitation...     

Pd–NPs@MMT–K10 Catalysis of Suzuki–Miyaura Cross-coupling Reaction: In Situ Generation and Ex Situ Use

Catalysis Letters - Due to high surface area and low swelling property, Montmorillonite–K10 (MMT–K10) has been gaining widespread applications in heterogeneous catalysis as a material...     

Crystal Nucleation in Soda–Lime–Silica Glass at Temperatures below the Glass Transition Temperature

The effect of crystal nuclei formed during the production of glass on the kinetics of nucleation of crystals in it at temperatures below the glass transition temperature is studied. A glass composition of 22.4Na2O ⋅ 28.0CaO ⋅ 49.6SiO2 (mol %) is studied (glass transition temperature 540°C). Using the development method, the dependence of the number of nucleated crystals on the heat treatment time is determined at a temperature of 500°C. The nuclei of crystals formed during the production of glass lead to an unusual, in the form of a step, initial section of the curve N(t). The rate of stationary nucleation of crystals with a long time of nucleation heat treatment exceeding the induction period of crystal nucleation is determined. The reasons for the unusual initial nature of the dependence N(t) are discussed. The data obtained make it possible to expand the temperature dependences of the stationary rate and the induction period of crystal nucleation for the given glass toward low temperatures.     

Crystallization of Eutectic Structures in the LaB6–W2B5–NbB2 System

Glass Physics and Chemistry - Crystallized alloys in the LaB6–W2B5–NbB2 system are obtained by melting in an electric arc discharge and rapid cooling in an inert gas (Ar) flow. The...     

Hierarchically Grown Ni–Mo–S Modified 2D CeO2 for High-Efficiency Photocatalytic Hydrogen Evolution

Catalysis Letters - Through a simple solvothermal method, the bimetallic sulfide nanomaterial (Ni–Mo–S) was successfully grown on the surface of CeO2 to restrain the severe...     

Glass Formation in the PbO–GeO 2 System

The glass-forming region in the PbO–GeO2 system is studied. To increase the glass-forming limit in this system, the tempering rate of the samples has to be increased using special methodological practices. The dependence of the temperature of the synthesis of lead germanate glass on the PbO content is obtained. It is shown that the corrosion of alumina crucibles proceeded during the synthesis of lead germanate glass. The dependence of the thickness of the corroded layer of the alumina crucible wall on the time of the synthesis of the glass of the 55PbO · 45GeO2 composition, mol % at 900°С is obtained. It is proved that the obtained glass is X-ray amorphous within the whole range of compositions in the PbO–GeO2 system.     

Influence of Xerogel Synthesis Conditions in the ZrO 2 –Y 2 O 3 –CeO 2 System on the Properties of Powders and Ceramics Based on Them

Xerogels in the ZrO2–Y2O3–CeO2 system are obtained by coprecipitation. The influence of the synthesis method on the acid-base xerogel surface properties are studied. The sinuous dependence of the Lewis and Brønsted site content on the particle surface on the conditioning time of precipitates in the mother liquor and the presence of subsequent low-temperature processing is established. The relationship is established between the resulting ceramics properties, precipitate processing conditions, and the functional xerogel structure.     

Ternary SO42−–ZrO2–TiO2 Solid Super Acid Catalyst for One-Step Synthesis of Adipicdihydrazide

Catalysis Letters - An efficient SO42−–ZrO2–TiO2 super acid catalyst was fabricated via simple impregnation precipitation strategy and applied in one-step synthesis of...     

One-Pass Conversion of Benzene and Syngas to Alkylbenzenes by Cu–ZnO–Al2O3 and ZSM-5 Relay

Catalysis Letters - Alkylbenzenes have a wide range of uses and are the most demanded aromatic chemicals. The finite petroleum resources compels the development of production of alkylbenzenes by...     

Non-oxidative Decomposition of CH4 Over CeO2 and CeO2–SiO2 Supported Bimetallic Ni–Mo Catalysts

Catalysis Letters - The development of highly active and durable catalysts for H2 production through CH4 decomposition process is still a great challenge. In this study, CeO2 and CeO2–SiO2...     

Diffusion process in enzyme–metal hybrid catalysts

Enzyme–metal hybrid catalysts bridge the gap between enzymatic and heterogeneous catalysis, which is significant for expanding biocatalysis to a broader scope. Previous studies have demonstrated that the enzyme–metal hybrid catalysts exhibited considerably higher catalytic efficiency in cascade reactions, compared with that of the combination of separated enzyme and metal catalysts. However, the precise mechanism of this phenomenon remains unclear. Here, we investigated the diffusion process in enzyme–metal hybrid catalysts using Pd/lipase-Pluronic conjugates and the combination of immobilized lipase (Novozyme 435) and Pd/C as models. With reference to experimental data in previous studies, the Weisz–Prater parameter and efficiency factor of internal diffusion were calculated to evaluate the internal diffusion limitations in these catalysts. Thereafter, a kinetic model was developed and fitted to describe the proximity effect in hybrid catalysts. Results indicated that the enhanced catalytic efficiency of hybrid catalysts may arise from the decreased internal diffusion limitation, size effect of Pd clusters and proximity of the enzyme and metal active sites, which provides a theoretical foundation for the rational design of enzyme–metal hybrid catalysts.     

Self-Cleaning Surfaces with Superhydrophobicity of Ag–TiO2 Nanofilms on the Floor Ceramic Tiles

Glass Physics and Chemistry - The goal of this study was the surface modification of industrial floor ceramic tiles by sol-gel dip coating method to improve the antibacterial and hydrophobicity...     

Multicomponent polyurethane–carbon black composite as piezoresistive sensor

Polymer Bulletin - Composite of carbon black (CB) dispersed into a multicomponent polyurethane matrix combines the good mechanical properties of the polymer, such as elasticity, with the electrical...     

NiCo2O4@quinone-rich N–C core–shell nanowires as composite electrode for electric double layer capacitor

The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability. Considering the close connection between their performance and the amount of carbon material loaded on the electrodes, in this work, NiCo₂O₄ nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction. Then, the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo₂O₄ nanowires, and the obtained composite was used as electrode for electric double layer capacitor. The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF∙cm^–2 at the current density of 1 mA∙cm^–2. The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW∙h∙cm^–3 at a power density of 180 mW∙cm^–3. The assembled symmetric capacitor exhibited a capacitance retention of 88.96% after 10000 charge/discharge cycles at the current density of 20 mA∙cm^–2. These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.     

Water-Dispersible Pd–N-Heterocyclic Carbene Complex Immobilized on Magnetic Nanoparticles as a New Heterogeneous Catalyst for Fluoride-Free Hiyama,Suzuki–Miyaura and Cyanation Reactions in Aqueous Media

Catalysis Letters - Pd–N-heterocyclic carbine complex immobilized on magnetic nanoparticles is synthesized and characterized by different techniques such as FT-IR, XPS, TEM, EDX, FESEM, VSM,...     

Synthesis and Study of a Polypyrrole–Aluminum Oxide Nanocomposite Film on an Aluminum Surface

Using the method of electrochemical anodization, aluminum oxide porous films are obtained in a sulfuric acid solution. The morphology of the aluminum oxide surface is studied by the method of scanning electron microscopy. The high-quality elemental analysis of the initial and oxidized Al films is performed using the method of electron microprobe analysis. A protective composite polypyrrole-aluminum oxide film is produced on the aluminum surface on top of a porous aluminum oxide film in the galvanostatic oxidation mode by the electrochemical synthesis method. The properties of the polypyrrole–aluminum oxide composite film are studied by the methods of voltammetry, as well as impedance and FTIR spectroscopy.     

Solvent-Driven Selectivity on the One-Step Catalytic Synthesis of Manoyl Oxide Based on a Novel and Sustainable “Zeolite Catalyst–Solvent” System

Catalysis Letters - Application of a novel “zeolite catalyst–solvent” system for the sustainable one-step synthesis of the terpenoid manoyl oxide, the potential precursor of...     

Fabrication and physicochemical properties of glass fabric–multifunctional epoxy resin composite

Polymer Bulletin - (2E,6E)2,6-Bis(4-amino benzylidene)cyclohexanone (BABC) was synthesized and used as a curing agent for tetrafunctional epoxy resin of bisphenol-C-formaldehyde (EBCF). Cured resin...