CoZr nanocomposites in a ceramic-metal AlO(OH)/Al matrix with a different Co/Zr ratio and its potential for syngas processing.

We investigated the possibility of synthesizing Co nanoparticles in CoZrH/AlO(OH)/Al ceramic-metal catalysts and controlling the catalytic properties of these nanoparticles in syngas conversion by changing the Co/Zr ratio. The CoZr nanocomposites were obtained from metal powders by mechanochemical activation in a high-energy mill under an argon atmosphere, followed by treatment with hydrogen at high pressure and room temperature. Ceramic-metal catalysts were prepared by mixing the corresponding CoZrH powder nanocomposite (30 wt%) with powdered aluminum (70 wt%), hydrothermal treatment of the mixture and subsequent calcination.

Catalytic co-combustion of biomass and brown coal in a fluidized bed: Economic and environmental benefits.

The work is devoted to the study of combustion of brown coal, pine sawdust, and their mixtures in a fluidized bed of catalyst at 600-750°С. It is shown that an increase in the content of sawdust in a mixture with brown coal leads to an increase in the burnout degree of solid fuel from 94.4% to 99.

Depolymerization of Pine Wood Organosolv Lignin in Ethanol Medium over NiCu/SiO and NiCuMo/SiO Catalysts: Impact of Temperature and Catalyst Composition.

The process of thermocatalytic conversion of pine ethanol lignin in supercritical ethanol was studied over NiCu/SiO and NiCuMo/SiO catalysts bearing 8.8 and 11.7 wt.

The Relationship between the Structural Characteristics of α-FeO Catalysts and Their Lattice Oxygen Reactivity Regarding Hydrogen.

In this paper, the relationship between the structural features of hematite samples calcined in the interval of 800-1100 °C and their reactivity regarding hydrogen studied in the temperature-programmed reaction (TPR-H) was studied. The oxygen reactivity of the samples decreases with the increasing calcination temperature. The study of calcined hematite samples used X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and Raman spectroscopy, and their textural characteristics were studied also.

Approaches to the design of efficient and stable catalysts for biofuel reforming into syngas: doping the mesoporous MgAlO support with transition metal cations.

The mesoporous MgAlO support is promising for the design of efficient and stable to coking catalysts for natural gas and biofuel reforming into syngas. This work aims at doping this support with transition metal cations (Fe, Cr, Ti) to prevent the incorporation of Ni and rare-earth cations (Pr, Ce, Zr), loaded by impregnation, into its lattice along with providing additional sites for CO activation required to prevent coking. Doped MgAlMeO (Me = Fe, Ti, Cr) mesoporous supports prepared by the one-pot evaporation-induced self-assembly method with Pluronic P123 triblock copolymers were single-phase spinels.

Platinum(IV) Carbonato Complexes: Formation via the Addition of CO to the [Pt(OH)] Anion and Generation of Platinum(IV) Oxide Nanoparticles for the Preparation of Catalysts.

A combination of multinuclear nuclear magnetic resonance spectroscopy and theoretical calculation based on density functional theory was used for a speciation study of Pt in solutions prepared either by the interaction of [Pt(OH)] with gaseous CO in an alkaline solution of platinum(IV) hydroxide ([Pt(OH)(HO)]) or by the dissolution of [Pt(OH)(HO)] in an aqueous KHCO solution. The formed solutions contained coexisting Pt(IV) carbonato complexes with κ- and κ-coordination modes. The gradual condensation of mononuclear Pt species in such bicarbonate solutions resulted in the formation of PtO nanoparticles aggregating into a solid precipitate on prolonged aging.

Unusual Acid Sites in LSX Zeolite: Formation Features and Physico-Chemical Properties.

The advanced approach for the preparation of the NH form of highly crystalline LSX zeolite under gentle drying conditions (40 °C, membrane pump dynamic vacuum) is discussed. Decationization of this form at moderate temperatures led to the formation of Brønsted acid sites (BASs), whose concentration and strength were characterized by IR spectroscopy. It was found that a maximum concentration of three BASs per unit cell can be achieved at 200 °C prior to the initiation of zeolite structure degradation.

Crystallization of SAPO-11 Molecular Sieves Prepared from Silicoaluminophosphate Gels Using Boehmites with Different Properties.

In this article, we report the results of research the formation of silicoaluminophosphate gels under changing gel aging conditions and the influence of an aluminum source (boehmite), characterized by different properties. The samples of initial gels were characterized by XRF, X-ray diffraction, MAS NMR Al and P, and scanning electron microscopy (SEM). Products of crystallization were characterized by XRF, X-ray diffraction, MAS NMR Al and P, scanning electron microscopy (SEM), N-physical adsorption, and IR spectroscopy with pyridine adsorption.

Comprehensive Review on g-CN-Based Photocatalysts for the Photocatalytic Hydrogen Production under Visible Light.

Currently, the synthesis of active photocatalysts for the evolution of hydrogen, including photocatalysts based on graphite-like carbon nitride, is an acute issue. In this review, a comprehensive analysis of the state-of-the-art studies of graphic carbon nitride as a photocatalyst for hydrogen production under visible light is presented. In this review, various approaches to the synthesis of photocatalysts based on g-CN reported in the literature were considered, including various methods for modifying and improving the structural and photocatalytic properties of this material.

LaCoCuTiO/KIT-6 perovskites: synthesis and catalytic behavior in syngas conversion to higher alcohols.

Highly dispersed LaCoCuTiO/KIT-6 perovskites were synthesized by the citrate method with inert mesoporous KIT-6 addition. The KIT-6 matrix was removed by dissolution in 7% NaOH aqueous solution. The dispersity of perovskites probably varies depending on the largest cation and its content at the B position of the perovskite ABO3 structure.

Resistance Switching in Polycrystalline C12A7 Electride.

The memory (memristive) properties of an electride material based on polycrystalline mayenite (C12A7:e) were studied. The phase composition of the material has been confirmed by such methods as XRD, TEM, Raman, and infrared spectroscopy. The electride state was confirmed by conductivity measurements and EPR using a characteristic signal from F-like centers, but the peak at 186 cm, corresponding to an electride with free electrons, was not observed explicitly in the Raman spectra.

Model-Based Performance Analysis of Membrane Reactor with Ethanol Steam Reforming over a Monolith.

Membrane reactors (MR) with an appropriate catalyst are considered to be an innovative and intensified technology for converting a fuel into the hydrogen-rich gas with the simultaneous recovery of high-quality hydrogen. Characteristics of an asymmetric membrane disk module consisting of a gas-tight nanocomposite functional coating (Ni + Cu/NdWO mixed proton-electron conducting nanocomposite) deposited on a gas-permeable functionally graded substrate has previously been extensively studied at lab-scale using MRs, containing the catalyst in a packed bed and in the form of a monolith. The catalytic monolith consisted of a FeCrAl substrate with a washcoat and an Ni + Ru/PrCeZrO active component.

Highly Active Visible Light-Promoted Ir/-CN Photocatalysts for the Water Oxidation Reaction Prepared from a Halogen-Free Iridium Precursor.

A combination of the exceptional stability of -[Ir(HO)(NO)] together with thermolability of nitro and aqua ligands and high solubility in various solvents makes it promising as a brand-new chlorine-free precursor of iridium for the preparation of heterogeneous catalysts. In the current work, a new technique of -[Ir(HO)(NO)] preparation based on hydrothermal treatment of (NH)[Ir(NO)] was developed. For this purpose, the influence of reaction parameters such as the reaction time, temperature, and pH of the solution on the process of hexanitroiridate salt hydrolysis was investigated.

Sulfuric Acid Solutions of [Pt(OH)(HO)]: A Platinum Speciation Survey and Hydrated Pt(IV) Oxide Formation for Practical Use.

The systematic study of the platinum speciation in sulfuric acid solutions of platinum (IV) hydroxide {[Pt(OH)(HO)], HHPA} was performed with the use of a combination of methods. Depending on the prevailing Pt form, the three regions of HSO concentration were marked: (1) up to 3 M HSO forms unstable solutions gradually generating the PtO·HO particles; (2) 4-12 M HSO, where the series of mononuclear aqua-sulfato complexes ([Pt(SO)(HO)], where = 0···4) dominate; and (3) 12 M and above, where, along with [Pt(SO)(HO)] species, the polynuclear Pt(IV) species and complexes with a bidentate coordination mode of the sulfato ligand are formed. For the first time, the salts of the aqua-hydroxo Pt(IV) cation [Pt(OH)(HO)]SO (triclinic and monoclinic phases) were isolated and studied with a combination of methods, including the single-crystal X-ray diffraction.

Structural and transport properties of Nd tungstates and their composites with NiCuO obtained by mechanical activation.

Nd tungstates and molybdates are promising materials for hydrogen separation membranes due to their high protonic conductivity. This work aims at elucidating the structural, textural and oxygen transport features of NdWO, NdWMoO and (NdLa)WO and their composites with NiCuO synthesized by mechanical activation. The oxide materials obtained were distorted double fluorites but their composites with NiCuO possess a complex phase composition.

Composite photocatalysts based on Cd Zn S and TiO for hydrogen production under visible light: effect of platinum co-catalyst location.

Ternary composite photocatalysts based on titania and solid solutions of CdS and ZnS were prepared and studied by a set of physicochemical methods including XRD, XPS, HRTEM, UV-vis spectroscopy, and electrochemical tests. Two synthetic techniques of platinization of Cd Zn S/TiO were compared. In the first case, platinum was deposited on the surface of synthesized Cd Zn S ( = 0.

Mayenite Synthesis from Hydroxide Precursors: Structure Formation and Active Sites on Its Surface.

We studied the formation process of a mayenite structure from hydroxide precursors in different gas media. According to X-ray diffraction data, this method allows a well-crystallized mayenite (CaAlO or C12A7) phase to be obtained at low (500-900 °C) temperatures with an insignificant impurity of CaO. It was shown that the lattice parameters for C12A7 obtained in an inert atmosphere (Ar) were lower when compared with similar samples in the air.

An Experimental Performance Study of a Catalytic Membrane Reactor for Ethanol Steam Reforming over a Metal Honeycomb Catalyst.

The present study deals with the combination of ethanol steam reforming over a monolithic catalyst and hydrogen separation by membrane in a lab-scale catalytic membrane reactor (CMR). The catalyst was comprised of honeycomb thin-walled Fechralloy substrate loaded with Ni + Ru/PrCeZrO active component. The asymmetric supported membrane consisted of a thin Ni-Cu alloy-Nd tungstate nanocomposite dense permselective layer deposited on a hierarchically structured asymmetric support.

Ni-Cu High-Loaded Sol-Gel Catalysts for Dehydrogenation of Liquid Organic Hydrides: Insights into Structural Features and Relationship with Catalytic Activity.

The heightened interest in liquid organic hydrogen carriers encourages the development of catalysts suitable for multicycle use. To ensure high catalytic activity and selectivity, the structure-reactivity relationship must be extensively investigated. In this study, high-loaded Ni-Cu catalysts were considered for the dehydrogenation of methylcyclohexane.

Cellulose-Based Hydrogels and Aerogels Embedded with Silver Nanoparticles: Preparation and Characterization.

The paper presents the preparation and characterization of novel composite materials based on microcrystalline cellulose (MCC) with silver nanoparticles (Ag NPs) in powder and gel forms. We use a promising synthetic conception to form the novel composite biomaterials. At first MCC was modified with colloidal solution of Ag NPs in isopropyl alcohol prepared via metal vapor synthesis.

Applicability of modified carbon sorbent for removing potentially toxic biologically active molecules of aromatic structure from blood plasma.

The modification of the mesoporous carbon sorbent with 3-phenylpropanoic acid was carried out in order to create preparations of complex, prolonged action, exhibiting detoxifying, antibacterial, and antifungal properties due to the applied modifier, which is capable of migrating into the solution and exhibiting its own biospecific properties. A technique was developed for fixing 3-phenylpropionic acid (PhPA) on a carbon support by its adsorption from solution. Three types of sorbents with various content of the modifier (PhPA) and the sorbent without modifier were studied.

Comparative Study of the Photocatalytic Hydrogen Evolution over CdMnS and CdS-β-MnO-MnOOH Photocatalysts under Visible Light.

A series of solid solutions of cadmium and manganese sulfides, CdMnS (x = 0-0.35), and composite photocatalysts, CdS-β-MnO-MnOOH, were synthesized by precipitation with sodium sulfide from soluble cadmium and manganese salts with further hydrothermal treatment at 120 °C. The obtained photocatalysts were studied by the X-ray diffraction method (XRD), UV-vis diffuse reflectance spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N low temperature adsorption.

Combustion of sewage sludge in a fluidized bed of catalyst: ASPEN PLUS model.

This paper presents the results of the simulation of a sewage sludge combustion plant with a productivity of 6 tons per hour using the ASPEN Plus. It is shown that catalytic combustion technology can be used for the efficient utilization of mechanically dehydrated sludge with the moisture of ~75% in autothermal mode (without the use of additional fuel). At the same time, the plant for utilization of 6.

New titania-based photocatalysts for hydrogen production from aqueous-alcoholic solutions of methylene blue.

A series of CuO -TiO photocatalysts were prepared using fresh and thermally activated Evonik Aeroxide P25 titanium dioxide. The photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, XANES, diffuse reflectance spectroscopy, and N adsorption technique. Photocatalytic activity of the samples was tested in hydrogen production from aqueous-alcoholic solutions of methylene blue under UV radiation ( = 386 nm).

Methylammonium Polyiodides: Remarkable Phase Diversity of the Simplest and Low-Melting Alkylammonium Polyiodide System.

Newly discovered methylammonium polyiodides (MAI) are unique precursors for innovative solvent-free technologies in perovskite photovoltaics because MAI are liquids at room temperature and demonstrate high chemical reactivity. We investigated the features of an MAI-I system and built up a first phase diagram in wide temperature and composition ranges using data from differential scanning calorimetry, single-crystal X-ray diffraction, and visual thermal analysis. The phase diagram has been found to differ drastically from that of any related systems owing to the unique propensity of methylammonium toward forming a diversity of polyiodides with complicated crystal structures, namely, MAI, MAI, MAI, and MAI, found in this system for the first time.