E. A. Tveritinova

Catalytic conversion of C(2)-C(3) alcohols on detonation nanodiamond and its modifications

The catalytic activity of detonation nanodiamond and its modifications obtained through treatment with hydrogen or air at elevated temperatures is studied in the conversion of C2-C3 alcohols. The catalysts were characterized by means of electron microscopy, optical (FTIR) spectroscopy, elemental analysis and pulse microcatalytic method. It has been established that nanodiamond exhibits high catalytic activity in the conversion of alcohols. The oxidizing and reducing treatment of nanodiamond changes its activity and selectivity, and the activity of oxidized nanodiamond is considerably higher than that of reduced nanodiamond.

Catalytic properties of a copper-carbon system formed by explosive decomposition of copper acetylide

The catalytic properties of a copper-carbon system formed by the explosive decomposition of copper acetylide in the propanol-2 dehydrogenation and dehydration reaction were studied by the pulse microcatalytic method over the temperature range 60–350°C. The extent of conversion was as high as 85%. It was established that the ratio between the catalytic conversion channels of propanol-2 depended on the method of acetylide decomposition (explosion in air or in vacuum).

Effect of the Detonation Nanodiamond Surface on the Catalytic Activity of Deposited Nickel Catalysts in the Hydrogenation of Acetylene

A comparative study is performed of the catalytic activity of nanosized nickel deposited on detonation synthesis nanodiamond (DND) and coal (CSUG) produced by burning sugar and crystalline quartz in the hydrogenation of acetylene. Nanosized nickel is obtained through the thermal decomposition of nickel formate under a dynamic vacuum. The catalysts are studied by means of scanning electron and transmission electron microscopy, X-ray fluorescence, IR-spectroscopy, X-ray diffraction, and pulse microcatalytic method. It is shown that Ni/DND is an active catalyst of acetylene hydrogenation, considerably surpassing Ni/quartz and Ni/CSUG. The apparent activation energy of the hydrogenation of acetylene is calculated, and the region of the reaction are determined for all catalysts. It is found that the influence of the structure and nature of a functional coating of nanodiamond on the catalytic activity of Ni/DND deposited catalyst in the hydrogenation of acetylene. The ability of Ni/DND to hold active hydrogen is detected.

Conversion of C2-C4 alcohols over copper-containing catalysts on carbon and fluorocarbon fibers

Carbon and fluorocarbon fibers were used as carriers for the preparation of copper catalysts from copper oxalate as precursor. The catalytic properties of catalyst were studied in the reaction of the dehydrogenation of C2-C4 alcohols by the pulsed microcatalytic method. The effect of the copper content in the catalyst, the reaction temperature on the degree of conversion, and the relation of the reaction channels were studied. The electron microphotographs were obtained, specific surfaces were measured, and X-ray pictures and infrared spectra of catalysts were taken. The activity of the catalysts on the carbon and fluorocarbon fibers in the dehydration-dehydrogenation reactions of C2-C4 alcohols was comparatively estimated. It was shown that the selectivity of the products from the dehydrogenation reaction is higher for the Cu-fluorocarbon fiber catalyst.

A copper catalyst on nonporous supports based on copper oxalate as a precursor

A method for obtaining copper catalysts on nonporous supports by the thermal decomposition of copper oxalate in the absence of oxygen was suggested. The catalytic properties of the catalyst were studied in the model reaction of the conversion of propanol-2 into acetone and propylene. The influence of the content of copper in the catalyst, reaction temperature, and conditions of oxalate decomposition on the degree of alcohol conversion and ratio between reaction channels was studied. Electron photomicrographs were obtained, specific surface areas were measured, and X-ray powder patterns of the catalyst were recorded.

The Electron Acceptor and Catalytic Properties of Zirconium Dioxide Modified with Aluminum and Gallium Oxides

The electron acceptor properties of the mixed oxide systems 20 mol % M2O3-ZrO2 (M = Al, Ga) and 10 mol % M2O3-10 mol % Al2O3-ZrO2 (M = Ga, Y) were studied by recording the EPR spectra of paramagnetic complexes of adsorbed anthraquinone. The EPR data were compared with the catalytic activity of the mixed oxides in the decomposition of propanols and butanols in a pulsed microcatalytic reactor. The Al2O3-ZrO2 and Ga2O3-ZrO2 solid solutions were found to be metastable and decompose as the temperature of calcining increased or a third component was introduced. Correspondence between the EPR data and catalytic experiment results was established. This correspondence substantiates the occurrence of the segregation of the Al2O3 and Ga2O3 amorphous phases on the surface of zirconia, which accompanies the decay of the M2O3-ZrO2 (M = Al, Ga) metastable solid solutions. The Al2O3-ZrO2 solid solution decomposes more readily than Ga2O3-ZrO2.

Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2–C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

Catalytic conversion of aliphatic alcohols on carbon nanomaterials: The roles of structure and surface functional groups

Carbon nanomaterials with the structure of graphene and different compositions of the surface groups are used as catalysts for the conversion of С2–С4 aliphatic alcohols. The conversions of ethanol, propanol- 1, propanol-2, butanol-1, butanol-2, and tert-butanol on carbon nanotubes, nanoflakes, and nanoflakes doped with nitrogen are investigated. Oxidized and nonoxidized multiwalled carbon nanotubes, nanoflakes, and nanoflakes doped with nitrogen are synthesized. X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning and transmission electronic microscopies, Brunauer–Emmett–Teller method, derivatographic analyses, and the pulsed microcatalytic method are used to characterize comprehensively the prepared catalysts. It was established that all of the investigated carbon nanomaterials (with the exception of nondoped carbon nanoflakes) are bifunctional catalysts for the conversion of aliphatic alcohols, and promote dehydration reactions with the formation of olefins and dehydrogenation reactions with the formation of aldehydes or ketones. Nanoflakes doped with nitrogen are inert with respect to secondary alcohols and tert-butanol. The role of oxygen-containing and nitrogen-containing surface groups, and of the geometrical structure of the carbon matrix of graphene nanocarbon materials in the catalytic conversion of aliphatic alcohols, is revealed. Characteristics of the conversion of aliphatic alcohols that are associated with their structure are identified.

Effect of structure and surface properties on the catalytic activity of nanodiamond in the conversion of 1,2-dichloroethane

The catalytic activity of a detonation nanodiamond and its Ni-containing forms in the conversion of 1,2-dichloroethane is studied and compared with the activity of other carbon and nanocarbon materials: carbon nanotubes, “Dalan” synthetic diamond, and fluorinated graphite. The surface and structure of the carbon materials are characterized using XRD, diffuse reflectance IR spectroscopy, XPS, BET, and TPR. The catalytic properties of the materials are studied using the pulsed microcatalytic method. It is found that the synthetic diamond, the nanodiamond, and its Ni-containing forms are catalysts for dichloroethane conversion in a nitrogen atmosphere, where the main product is ethylene. It is noted that the catalytic activity of deactivated diamond catalysts is restored after hydrogen treatment. It is shown that the carbon structure of the nanodiamond and the “Dalan” synthetic diamond with hydrogen groups located on it plays a key role in the dichloroethane conversion. It is found that the nanodiamond acts simultaneously as a catalyst and an adsorbent of chlorine-containing products of dichloroethane conversion.