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The paper comparatively assesses the physicochemical properties of natural aluminosilicate nanotubes (halloysite) provided by domestic (HNT-Ch) vs. foreign (HNT-A) manufacturers, as well as the catalytic activity of ruthenium catalysts synthesized therefrom. The composition, structure, and textural properties of the materials were measured by a combination of physicochemical methods, such as TEM, ED–XRF, low-temperature nitrogen adsorption/desorption, and H2–TPR. The activity of the synthetic catalysts was examined in benzene hydrogenation at 80°C and a hydrogen pressure of 3 MPa in both a hydrocarbon and aqueous–hydrocarbon system. The catalysts supported on HNT-Ch and HNT-A were found to have similar physicochemical properties and to exhibit high activity in benzene hydrogenation, both in the monophasic and biphasic systems, thus ensuring quantitative substrate conversion with 100% cyclohexane selectivity.

A methanol conversion catalyst based on natural aluminosilicate nanotubes and H–ZSM-5 zeolite was synthesized. Its textural, structural, and acid properties were studied by low-temperature nitrogen adsorption–desorption, transmission electron microscopy, X-ray diffraction analysis, and temperature-programmed ammonia desorption. The influence exerted on the methanol conversion and product distribution by the reaction temperature (380–460°С), pressure (0.1–0.5 MPa), and feed space velocity (0.5–1 h–1) was studied. The catalyst based on halloysite aluminosilicate nanotubes showed high selectivity in formation of both lower olefins and aromatic hydrocarbons.

Bifunctional zeolite-containing catalysts based on transition metal sulfides were synthesized, their physicochemical characteristics were determined, and the catalytic properties toward n-hexadecane hydroconversion were examined. ZSM-5, Beta, and NH4NaY zeolites were tested as acidic components of the catalysts. The highest selectivity toward isomerization reaction was afforded by the NH4NaY zeolite-containing sulfide-based catalyst. With the view to controlling the selectivity toward cracking and isomerization reactions, the influence of the presence of nitrogen-containing bases in the feedstock was evaluated.

Hierarchical composite materials based on ordered aluminosilicates of the Al–MCM-41 type and halloysite nanotubes (HNTs) with different Al–MCM-41/halloysite weight ratios have been synthesized and studied as components of supports of platinum catalysts for the isomerization of the C8 aromatic fraction of reforming. At each synthesis stage, the materials have been characterized by transmission electron microscopy (TEM), low-temperature nitrogen adsorption, X-ray fluorescence analysis, X-ray diffraction (XRD) analysis, and temperature-programmed desorption of ammonia (NH3-TPD). Catalyst systems with an Al–MCM-41/HNT weight ratio of 90 : 10 wt % have shown the highest efficiency in xylene isomerization providing a higher conversion of ethylbenzene and m-xylene than the conversion provided by the HNT-based catalyst. It has been found that the synthesized catalysts exhibit a higher selectivity for the target product of the process—p-xylene—than the selectivity of a commercial counterpart in a temperature range of 360–440°C. The maximum p-xylene selectivity (70%) has been achieved in the presence of a Pt/Al–MCM-41/HNT(90 : 10)/Al2O3 catalyst at 360°C.

Ru-containing catalysts based on aluminosilicate halloysite nanotubes (HNTs) are synthesized by preliminary functionalization of the support surface by aminopropyltriethoxysilane (APTES) followed by the microwave-assisted deposition of ruthenium to provide the intercalation of metal nanoparticles into the inner space of nanotubes. The composition and structure of the synthesized catalysts are studied by X-ray fluorescent analysis, low-temperature nitrogen adsorption/desorption, transmission electron microscopy, and hydrogen temperature-programmed reduction. The activity of the catalysts in benzene hydrogenation at a temperature of 80°С and a hydrogen pressure of 3 MPa both in the hydrocarbon medium and in the two-phase system with water is studied. It is shown that, in the presence of water, the hydrogenating activity of the catalyst based on modified halloysite nanotubes is considerably higher than that of the sample prepared using the initial halloysite as a support.

The activity of unsupported Ni–Mo sulfide catalysts is studied in the hydroconversion of benzothiophene and dibenzothiophenes in the temperature range of 340–380°С and at an increased H2 pressure and in the СО/H2О system. The structure of dispersed catalysts formed by the in situ high-temperature decomposition of oil-soluble precursors (molybdenum hexacarbonyl, nickel naphthenate) is investigated by TEM. Effects of СО/H2О molar ratio, water mass content in the system, and CO pressure on the activity of the catalysts and yields of the products are explored. It is shown that, in the СО/H2О system, the highest conversion of benzothiophene and dibenzothiophene is attained at a temperature of 380°С, a СО pressure of 5 MPa, and a СО/H2О molar ratio of 2. The introduction of alkyl substituents into a dibenzothiophene molecule causes a reduction in the rate of reaction that predominantly occurs via the hydrogenation of aromatic rings. The catalyst activities in hydrogenation under H2 pressure and in the СО/H2О system are comparable.

The composition, structure, catalytic activity, and stability of ruthenium catalytic systems prepared using natural aluminosilicate nanotubes as a support were studied. The influence of the preparation procedure on the morphology of ruthenium nanoparticles selectively formed inside mesoporous aluminosilicate nanotubes was examined. The activity and stability of catalysts in the model reaction of benzene hydrogenation in the presence of water [V(C6H6) = V(H2O), 80°C, hydrogen pressure 3.0 MPa, reaction time 3 h] were studied. The catalyst containing 1.02 wt % ruthenium, prepared by reduction of the ruthenium ethylenediaminetetraacetate complex in a hydrogen stream at 400°С, exhibits higher activity (the benzene conversion in the 3-h reaction was 100%) and higher stability in the reaction (the benzene conversion after three reaction cycles was 95%) compared to the system with the similar ruthenium content (0.98 wt %) prepared by reduction with a sodium borohydride solution. The reduction with hydrogen leads to the formation of highly stable ruthenium nanoparticles with the mean diameter of 2 nm, tightly bound to the internal surface of aluminosilicate nanotubes.

The activity of unsupported Ni–Mo sulfide catalysts formed during the in situ decomposition of oil-soluble precursors (molybdenum hexacarbonyl, nickel naphthenate) in the hydrogenation of aromatic and naphthene-aromatic compounds is studied. The catalysts are characterized by HRTEM and XPS. Catalytic experiments are conducted at temperatures of 340–380°C and an increased pressure of ?? in the presence of water providing the in situ generation of hydrogen via the water-gas shift reaction. The catalysts exhibit a high activity in the hydrogenation of model substrates (methyl- and dimethyl-substituted naphthalenes and anthracene).

An ordered mesoporous aluminosilicate of the Al–MCM-41 type has been studied as a component of additives for of petroleum feedstock cracking catalysts. The influence of the nature of the modifying material and its concentration on the activity of the additive has been investigated. It has been shown that the use of bimetallic additives on the basis of ordered mesoporous aluminosilicate makes it possible to reduce the sulfur content in liquid cracking products of vacuum gas oil by 37% more effectively in comparison with that for an additive-free industrial catalyst.

A comparative study of the reaction of catalytic epoxidation of cyclohexene with hydrogen peroxide in water and ionic liquids containing dihydrogen phosphate anions, such as trimethylammonium dihydrogen phosphate, diethylammonium dihydrogen phosphate, and N-methylpyrrolidonium dihydrogen phosphate has been performed. It has been shown that as high a cyclohexane epoxide yield as 80% with a selectivity close to quantitative can be obtained under optimum conditions by controlling the ratio of the ionic liquid components.