One of the steps in scaling the technology for the synthesis of zeolite-containing catalysts from the laboratory to commercial level is support forming. In this study, halloysite nanotubes and aluminum oxide were used as binders for preparing a support based on MFI (ZSM-5) zeolite. The Pt catalysts (Pt/ZSM-5/Al2O3 and Pt/ZSM-5/Hall) were tested in isomerization of the aromatic C8 fraction. The forming of supports influenced not only mechanical but also physicochemical properties of the catalysts. On introducing binders into the catalytic system, the fraction of mesopores in the total pore volume of the supports increased, the acidity of the samples decreased, and the ratio of the amounts of the weak and strong acid sites changed. The use of aluminum oxide and halloysite as binders leads to different pathways of the transformation of the aromatic feedstock. The main side reactions observed in the presence of Pt/ZSM-5/Al2O3 and Pt/ZSM-5/Hall catalysts are hydrocracking of alkylaromatic hydrocarbons and their transalkylation/disproportionation, respectively. The best results were obtained at 380°C and feed space velocity of 6 h–1 with Pt/ZSM-5/Hall: p-/о-xylene ratio 1.05, loss of xylenes 4.31

The MOR-type zeolite was synthesized by a template-free method using natural aluminosilicate halloysite nanotubes (HNT) as a hard template and a source of aluminum and silicon. Samples were studied using a complex of physicochemical methods of analysis: XRD, TEM, N2 physisorption, NH3-TPD and XRF. Specific BET surface area of MOR prepared using HNT is 306 m2/g, mesopores in the MOR:HNT accounted for 30 % of the total pore volume. Based on the synthesized materials (MOR, MOR:HNT and MOR + HNT), Pt-containing catalysts were prepared. The catalysts were investigated in the gas-phase isomerization of C-8 aromatic fraction in a temperature range of 360-420 degrees C, varying LHSV from 2 to 6 h-1, at H2 pressure of 1 MPa and hydrogen/ feedstock volume ratio of 900 nl/l. The prepared catalysts demonstrated strong activity in ethylbenzene trans-formation (more than 95 %), while providing a high yield of p-xylene (more than 95 % of thermodynamic value).

Iron- and Cu–Zn-containing carbon dioxide hydrogenation catalysts based on natural aluminosilicate nanotubes and zeolite H-ZSM-5 are synthesized. Their textural and acidic properties are studied via low-temperature nitrogen adsorption–desorption, temperature-programmed desorption of ammonia, temperature-programmed reduction of hydrogen, and elemental analysis. The effect the temperatures of the reaction have on the conversion of CO2 and distribution of its product is studied. Catalysts based on aluminosilicate halloysite nanotubes exhibit methanol and С2–С4 hydrocarbon selectivities of 88 and 16%, respectively.

Micro-mesoporous zeolite with ZSM-5 morphology was successfully synthesized by soft template and template -free methods using natural halloysite aluminosilicate nanotubes as a hard template and a source of aluminum and silicon. Formation of ZSM-5 crystal structure was confirmed by XRD. Textural properties and structural characteristics of functional materials, supports, and Pt-containing catalysts were examined by N2 physisorption, NH3-TPD, Py-FTIR, TEM, SEM, XRF techniques. Specific BET surface area of ZSM-5 zeolite prepared using TPABr as an organic template (ZSM-5(t):HNT) is 583 m2/g, whereas for the template-free counterpart (ZSM-5(tf):HNT) it reaches 225 m2/g. According to the Py-FTIR data, concentrations of Bronsted acid sites for ZSM-5(t):HNT and ZSM-5(tf):HNT are 295 and 93 mu mol/g, whereas concentrations of Lewis acid sites are 79 and 41 mu mol/g, respectively. Activity and selectivity of Pt catalysts based on the micro-mesoporous ZSM-5 zeolite-derived sup-ports were evaluated in isomerization of C-8 aromatic fraction depending on the process conditions (tempera-ture, feed space velocity). Because of the hierarchical micro-mesoporous structure, both catalysts provide xylenes transformation through the two isomerization routes (intra-and intermolecular). However, for the catalyst based on support synthesized through the template-free methods, the monomolecular reaction route is more preferable, and therefore the number of side reactions (disproportionation, transalkylation, and dealkylation) decreases.

A number of catalyst supports for hydroisomerization of C 8 aromatics were synthesized using various binders such as alumina, silica (pyrogenic, colloidal, and ordered mesoporous MCM-41), and natural aluminosilicate halloysite nanotubes (HNTs). These supports were examined by relevant physicochemical analytical methods, including transmission electron microscopy, low-temperature nitrogen adsorption/desorption, ammonia temperature-programmed desorption, and energy dispersive X-ray fluorescence spectrometry. The mechanical crushing strength of the samples was determined. The support synthesized with HNTs as a binder exhibited a significant percentage of mesopores, moderate acidity, and relatively high mechanical strength.

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.

A bizeolite catalyst based on ZSM-5 and ZSM-12 was designed to maximize the yield of valuable aromatics from ethylbenzene (EB) rich feedstocks for the first time. The catalyst Pt/ZSM-5:ZSM-12/Al2O3 was characterized by X-ray diffraction (XRD), nitrogen physisorption, temperature-programmed desorption of ammonia (TPD-NH3), transmission and scanning electron microscopy (TEM and SEM), X-ray fluorescence analysis (XRF), Fourier-transformed infrared spectroscopy (FTIR) and Al-27 magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The catalyst and its components were tested in isomerization of an industrial C-8 aromatic cut (C8-Ar) and feedstocks with high EB content. The catalyst demonstrated higher conversion of EB and m- xylene (MX) compared with an industrial catalyst and higher selectivity to dealkylation products.

A micro-mesoporous composite consisting of ZSM-5 zeolite and halloysite aluminosilicate nanotubes preliminarily treated with sulfuric acid was prepared and studied. The textural and structural characteristics of the composite, support, and catalyst based on it were examined by transmission electron microscopy, X-ray fluorescence elemental analysis, low-temperature nitrogen adsorption, and temperature-programmed ammonia desorption. The activity and selectivity that the Pt-containing catalyst based on the composite material obtained exhibits in isomerization of the C-8 aromatic fraction were evaluated. The results obtained using the micro-mesoporous catalyst under varied process conditions (temperature, feed space velocity) were compared to those obtained with the commercial catalyst. The micro-mesoporous catalyst Pt/ZSM-5 + Т-HNT/Al2O3 ensures quantitative conversion of ethylbenzene and increased, compared to the commercial analog, content of the para isomer in the mixture of xylenes at 360°С, feed space velocity of 6 h–1, hydrogen pressure of 1.0 MPa, and Н2/feed ratio of 1200 Ln.c. L–1.

Hydroprocessing catalyst supports based on aluminosilicate halloysite nanotubes with various alumina contents were synthesized. Their textural characteristics and acidic properties were investigated. The component composition and strength profile of cylindrical extrudates of the aluminosilicate supports were studied. The influence of the mass content of boehmite used as a binder on the physicochemical properties of the materials was established. The crush strength of the synthesized carriers based on aluminosilicate nanotubes was shown to be comparable or superior to those of industrial analogs.

The review deals with catalysts for isomerization of the C-8 aromatic fraction with the aim of obtaining valuable petrochemical products: o- and p-xylenes required for the subsequent synthesis of phthalic anhydride, dimethyl terephthalate, and terephthalic acid. Mono- and bimolecular mechanisms of xylene isomerization and ethylbenzene transformation pathways (isomerization, dealkylation, disproportionation, transalkylation, and hydrogenation) on various catalysts are discussed. Catalysts containing zeolites of structural types MFI, MTW, MOR, TUN, NES, CON, and BEA and composite materials based on zeolites and ordered mesoporous aluminosilicates (МСМ-41, МСМ-48) are considered. The effect that the structural and acid properties of support and the kind of the metal component and promoters exert on the course of the main and side reactions occurring in the course of isomerization of xylenes is demonstrated. Data on key commercial processes and catalysts are systematized.

The hierarchical MCM-41/ZSM-5 aluminosilicate synthesized via a double-template procedure using CTAB and TPAOH was applied as a support for Pt and Pd isomerization catalysts with metal loading of 0.5 wt.%. The formation of micro-ZSM-5, as well as meso-MCM-41 phases, was confirmed by XRD, TEM, SEM, and FT-IR. The element composition, textural properties and acidity both of MCM-41/ZSM-5 composite and noble metals supported catalysts were structurally characterized by TGA, N-2 sorption, XRF, and NH3-TPD. Examining the catalytic evaluation of MCM-41/ZSM-5 supported Pt and Pd catalysts in hydroisomerization of C8 aromatic fraction in a fixed bed flow-type unit at 280-420 degrees C, LHSV of 1-6 h(-1) and H-2:feed of 1200-3600, showed that the Pt catalyst is more active compared to its industrial counterpart and provides high m-xylene and ethyl benzene conversions predominantly with p-xylene formation at 340 degrees C with LHSV of 1.0 h(-1) (H-2/feed = 2400) as well as for LHSV of 3.5 h(-1) (H-2/feed = 1200).

A new class of multifunctional polymetallic catalysts was developed, the precursors of which are complex multicomponent intermetallic compounds prepared by self-propagating high-temperature synthesis. The catalysts based on Co and Ni exhibit high activity in the hydrogenation of CO2 to methane. The maximum yield of methane is observed at 250–350 °C with an almost complete conversion of CO2 and 100% selectivity. Hydrocarbons C1-C4, including unsaturated hydrocarbons (propylene and butadiene), were synthesized on the Co-Fe-La catalyst under a pressure to 2 MPa at 250–350 °C and the ratio CO2: H2 = 1: 1. The new class of catalysts is promising for the development of direct CO2 hydrogenation to heavy (liquid) alkanes and unsaturated hydrocarbons.

Highly efficient binder-free catalysts, based on zeolite Y, for the liquid-phase alkylation of benzene with ethylene have been synthesized. The catalysts have been modified by treating with aqueous solutions of hydrochloric and citric acids to remove extra-framework aluminum formed during the partial dealumination of zeolite Y. The synthesized catalysts have been tested in the alkylation of benzene with ethylene at a temperature of 200°C, a pressure of 2.5 MPa, a benzene : ethylene molar ratio of 5 : 1, and a benzene feed space velocity of 5 h−1. Over the modified catalyst, the ethylbenzene (EB) content in the alkylate increases by 27% and the EB selectivity increases by 5% compared to the initial Y zeolite.

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 C 8 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 (NH 3 -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)/Al 2 O 3 catalyst at 360°C.