N. D. Shcherban

Preparation, Physicochemical Properties and Functional Characteristics of Micromesoporous Zeolite Materials

Information in the literature on methods of preparation, structure, adsorption properties, and physicochemical characteristics of micromesoporous zeolite materials, including hierarchical porosity, has been summarized and analyzed. Special features were noted and promise was indicated for the use of mesoporous zeolites in catalysis, adsorption, and matrices for new micromesoporous materials. Possible directions for further investigation of the physical chemistry of zeolites and micromesoporous zeolite materials were examined.

Structure and Porosity of Silicon Carbide Produced by Matrix Method

Silicon carbide in the β

Effect of Dual Template Synthesis Conditions on Structural/Sorption Properties and Acidity of Microporous/Mesoporous ZSM-5/MCM-41 Aluminosilicates

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Influence of SBA-15 Zeolitization Conditions on Structural-Sorption and Acidic Properties of Micro-Mesoporous AluminosilicateS SBA-15/ZSM-5

modification with a developed surface and a large pore size was obtained by carbothermal reduction using mesoporous siliceous molecular sieves (SBA-15, KIT-6, MCF, SBA-3). The formation of silicon carbide with high porosity parameters is favored by the use of the KIT-6 mesoporous molecular sieve (MMS) with a three-dimensional structure and a mutually intersecting system of mesopores as matrix, by the close to the stoichiometric C/SiO2 ratio, and also by the higher level of filling with carbon in the pores of the siliceous MMS.

Porosity Enhancement of Silicon Carbide by Preparation in Micro-Mesoporous Zeolite-Like Matrices

A study was carried out on the photochemical reduction of CO2 involving titanium dioxide and metal–semiconductor nanostructures made using titanium dioxide. These metal–semiconductor nanocomposites display much higher activity than pure TiO2 particles. The activity of the composites studied in the photocatalytic reduction of CO2 increases in the series: TiO2/Ag < TiO2/Au < TiO2/Cu.

Preparation, Physicochemical Properties, and Functional Characteristics of Carbon Nitride: a Review

We have used a dual template synthesis method based on an initial ZSM-5 zeolite sol precursor in the presence of molecular and micellar templates to obtain X-ray amorphous and zeolite-containing microporous/mesoporous aluminosilicates having an ordered MCM-41 mesostructure, extended mesoporosity, small micropore volume, and medium-strength acid sites. We note a deviation from additivity for the change in micropore volume and the concentration of acid sites in the synthesized zeolitized samples.

New Approaches to Creation of Micro- and Mesoporous Functional Materials

Graphitic carbon nitride was prepared by bulk and hard template pyrolysis of melamine. The prepared g-C3N4 as well as N-doped carbon used for comparison exhibited a reasonable catalytic activity in the Knoevenagel condensation between benzaldehyde and ethylcyanoacetate yielding ethyl-α-cyanocinnamate (conversion of benzaldehyde up to 100%, yield of the desired product up to 51%). Under the studied reaction conditions, weak basic sites assigned as C–NC species are responsible for selective formation of the desired product. An increase of tertiary nitrogen content leads to an increase of benzaldehyde conversion with a simultaneous decrease of selectivity towards ethyl-α-cyanocinnamate due to a higher basicity. Carbon nitride obtained using silica as a hard template allows achieving the highest yield of the desired product (50.9%).

Effect of the Structure and Acidity of Micro-Mesoporous Alumosilicates on Their Catalytic Activity in Cumene Cracking

Partly zeolitized micro-mesoporous aluminosilicates SBA-15/ZSM-5 were synthesized by conversion of dry gel of template-containing SBA-15 in the presence of tetrapropylammonium hydroxide. They have a hexagonally ordered mesostructure and developed surface and mesoporosity for which the concentration and strength of the Brønsted and Lewis acid sites are higher than in AlSi-SBA-15. The formation of Brønsted acid sites of moderate strength in the samples with a low degree of zeolitization is due to the presence of ZSM-5 precursors as well as crystallites in the obtained aluminosilicates.