The fibrous hybrid material was synthesized by suspension radical styrene polymerization on the surface of cellulose microfibers. The resulting material was used to prepare a thermally stable and mechanically strong porous composite matrix that was employed as a carrier for further precipitation of the hygroscopic agents: CaCl2 and 1-butyl-3-methylimidazolium chloride. The obtained composite materials were used to capture atmospheric water at different relative humidity levels and extract fresh water. A composite material containing an ionic liquid (1-butyl-3-methylimidazolium chloride) as a hygroscopic agent demonstrated the best water absorption efficiency and reusability potential.

The micro-mesoporous support was prepared by sequential desilication-dealumination of ZSM-5/Al2O3 pellets. The Pt–Mo catalyst doped with Sn and Zn (Pt–Mo/ZSM-5/Al2O3) was synthesized by wetness co-impregnation technique with aqueous solutions of metal salts to load 0.5

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 elaboration of a low-cost and effective approach to synthesize hybrid composite materials based on the conventional thermoplastics and natural biopolymers is a sustainable alternative to the production of “traditional” plastics. Cellulose is one of the most abundant biopolymers. Its fibrils possess outstanding mechanical characteristics and, hence, attract considerable interest of researchers during recent decades. However, modification of the hydrophobic polymer matrix by cellulose fibrils is significantly complicated by the hydrophilic nature of the latter. In this study, we propose an effective and low-cost approach to the synthesis of polystyrene at the cellulose microfibrils composite material via the emulsion polymerization method. The obtained fibrous composite was comprehensively analyzed with FTIR spectroscopy, SEM, TGA, and DSC, and was further employed to produce sponge hybrid materials. We investigated the influence of the cellulose/polystyrene ratio on the density, porosity, pore volume, and water uptake of the obtained sponge materials. The sample containing 70 wt.% of cellulose demonstrated the best water absorption properties while preserving its shape, even after 24 h of floating on water. The produced sponge materials might be employed as sorption materials for the purification and desalination of waters of various origins, filtration, and collection of undesirable elements under specific industrial or natural conditions.

The oxidative dehydrogenation of alkanes is a prospective method for olefins production. CO2-assisted propane dehydrogenation over metal oxide catalysts provides an opportunity to increase propylene production with collateral CO2 utilization. We prepared the chromia catalysts on various mesoporous aluminosilicate supports, such as halloysite nanotubes, nanostructured core/shell composites of MCM-41/halloysite (halloysite nanotubes for the core; silica of MCM-41-type for the shell), and MCM-41@halloysite (silica of MCM-41-type for the core; halloysite nanotubes for the shell). The catalysts have been characterized by X-ray fluorescence analysis, low-temperature nitrogen adsorption, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption of ammonia, transmission electron microscopy with energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The catalysts’ performance in carbon-dioxide-assisted propane dehydrogenation has been estimated in a fixed-bed reactor at atmospheric pressure. The most stable catalyst is Cr/halloysite, having the lowest activity and the largest pore diameter. The catalyst, Cr/MCM-41/HNT, shows the best catalytic performance: having the highest conversion (19–88%), selectivity (83–30%), and space–time yield (4.3–7.1 mol C3H6/kg catalyst/h) at the temperature range of 550–700 °C. The highest space–time yield could be related to the uniform distribution of the chromia particles over the large surface area and narrow pore size distribution of 2–4 nm provided by the MCM-41-type silica and transport channels of 12–15 nm from the halloysite nanotubes.

Currently, Euro 5 (no more than 10 ppm sulfur content) and Euro 6 (less than 10 ppm sulfur content) diesel motor fuels are produced worldwide. High-quality diesel fuels are produced by removing sulfur compounds using a hydrodesulfurization process. This article is devoted to the study of hydrodesulfurization of diesel fuel containing 120 ppm of sulfur compounds in the presence of an Al-Ni-Mo-O catalyst with a 98% diesel fuel purification rate. According to the Langmuir–Hinshelwood–Panchenkov theory, a kinetic model of the process is developed with the calculation of the theoretical change in the entropy and enthalpy of the activation of the hydrodesulfurization process. The mathematical model, for the first time, takes into account the influence of the pressure of substances involved in the process on the transformation of sulfur-containing compounds. A mechanism for diesel fuel hydrotreating from sulfur-containing compounds is formulated using a generalized quantum-chemical principle. The hydrodesulfurization mechanism includes nine stages. The formulated mechanism and developed mathematical model of hydrotreating fully describe the reaction of the hydrodesulfurization of diesel fuel and show the possibility of regulating and controlling this industrially important process.

A scalable and efficient photocatalyst is a key factor for sustainable hydrogen production. For the first time, clay nanotube-templated mesoporous silica of MCM-41 type was used as an efficient carrier for photocatalytic nanoparticles. 4-5 nm CdS quantum dots (QDs) were synthesized in situ on the surface of this hierarchical aluminosilicate. The influence of the QD composition on the structural, spectral, and photocatalytic properties was investigated. A series of photocatalysts with various QD sizes (3.2-4.8 nm) and band gaps (2.46-2.66 eV) were obtained. Optimization of the CdS and cocatalyst (Ru) concentration resulted in an efficient visible light photocatalyst for hydrogen production. The photocatalytic activity was tested in an aqueous solution of Na2S/Na2SO3 under 30 W 450 nm diode illumination. The hydrogen evolution rate reached 2600 mu mol/g(cat).h (apparent quantum efficiency of 15%) for the system with 15.0 wt % of CdS doped with 0.2 wt % of Ru, which corresponds to the rate of hydrogen production of 17.1 mmol per hour counting on the active phase. The material demonstrated almost 100% efficiency of the catalytically active phase. It showed better catalytic activity in comparison to MCM-41 due to the hierarchical structure and presence of Al that stimulated electron transfer during the photocatalytic reaction.

Perovskite Solar Cells In article number 2101590, Hongqiang Wang and co-workers report stable perovskite solar cells with champion efficiency over 24% and moisture (75%) stability over 10 000 hours. Referencing the Chinese story “Nezha Conquers the Dragon King”, the tower of perovskite is strengthened by the interfacial embedding of laser-manufactured fluorinated gold clusters.

The aminosilane modified natural halloysite nanotubes were efficiently used as a template for ruthenium doped cadmium sulfide nanoparticles to prevent particles agglomeration and increase photocatalytic activity via better electron-hole pare separation. The photocatalysts were synthesized via a facile method and tested in H 2 evolution reaction under visible light irradiation with 0.1 mol L −1 Na 2 S and 0.1 mol L −1 Na 2 SO 3 as sacrificial agents. The as-prepared samples were characterized by transition electron microscopy, thermo-gravimetric analysis, photoluminescence spectrometry. The Ru–CdS nanoparticles synthesized on amino-modified halloysite nanotubes (Ru–CdS/Hall-APTES) had a high photocatalytic H 2 evolution rate of 932.3 µmol h −1 g −1 and apparent quantum efficiency (AQE) about 7.2% under monochromic 450 nm light irradiation. The well-enhanced photocatalytic activity of Ru–CdS/Hall-APTES composite could be attributed to the effective transfer and separation of photogenerated charge carriers, which is facilitated by Ru as a co-catalyst to assist photocatalytic H 2 evolution reaction. This work seems to provide an approach to prepare high-performance halloysite based nanocomposites towards different applications, like the as-studied photocatalytic production of hydrogen.

Tackling the interfacial loss in emerged perovskite-based solar cells (PSCs) to address synchronously the carrier dynamics and the environmental stability, has been of fundamental and viable importance, while technological hurdles remain in not only creating such interfacial mediator, but the subsequent interfacial embedding in the active layer. This article reports a strategy of interfacial embedding of hydrophobic fluorinated-gold-clusters (FGCs) for highly efficient and stable PSCs. The p-type semiconducting feature enables the FGC efficient interfacial mediator to improve the carrier dynamics by reducing the interfacial carrier transfer barrier and boosting the charge extraction at grain boundaries. The hydrophobic tails of the gold clusters and the hydrogen bonding between fluorine groups and perovskite favor the enhancement of environmental stability. Benefiting from these merits, highly efficient formamidinium lead iodide PSCs (champion efficiency up to 24.02%) with enhanced phase stability under varied relative humidity (RH) from 40% to 95%, as well as highly efficient mixed-cation PSCs with moisture stability (RH of 75%) over 10 000 h are achieved. It is thus inspiring to advance the development of highly efficient and stable PSCs via interfacial embedding laser-generated additives for improved charge transfer/extraction and environmental stability.

Industrial hydrogenation catalysts must be not only selective and active but also resistant to feedstock impurities, including water. We report the strategy of preparing catalytic core-shell nanoreactors based on hydrophobized aluminosilicate nanotubes loaded with ruthenium. The modification of halloysite with alkyltriethoxysilanes enhances hydrophobicity of the clay nanotubes (water contact angle up to 122 degrees) and enables their selective loading with 4-nm ruthenium particles. Such a core-shell tubular nanoreactors provide shielding of active sites from deactivation by admixed water and prevent metal leaching. Produced mesoscale catalysts were active in the hydrogenation of aromatics both in organic and aqueous media at 80 degrees C and a hydrogen pressure of 3 MPa. Benzene hydrogenation in the biphasic system with water resulted in a complete conversion with 100 % selectivity to cyclohexane over halloysite modified by C18-triethoxysilane supported ruthenium catalyst with turnover frequency (TOF) of 4371 h-1. This catalytic system remained stable after ten cycles of benzene hydrogenation, providing 98 % conversion. The demonstrated synthetic strategy is promising for the design of industrial catalysts for the hydroprocessing water-containing organic feedstock and may be upscaled due to the abundant availability of halloysite clay nanotubes.

Naphtha reforming is one of the most important industrial processes in refineries. The products include aromatic hydrocarbons such as benzene, toluene, and xylenes, which are frillier used as high octane additives to gasoline. To increase the efficiency of the process, it is necessary to develop a new method of naphtha reforming. In this work, we have proposed a mathematical model of catalytic refining of low-octane gasoline fracdons into high-octane fractions. The model is based on kinetic equations, established for commercial gasoline reforming in the presence of the platinum-rhenium catalyst on a γ-Al 2 O 3 carrier in the industrial-scale conditions. The equation: describe the dependence of the content of paraffinic, naphthenic, and aromatic hydrocarbon fractions on the process parameters, including volumetric rate and the reaction temperature. The mathematical model had been validated by comparing calculated results with the industrial data obtained from the commercial naphtha reforming production.

Eutrophication caused by the entry of nutrients into a water body may lead to algal bloom. Russia possesses the world’s second highest supply of renewable freshwater resources and has faced the problem of eutrophication for many years. Nevertheless, as far as we know, no general analysis of Russia’s algal bloom situation has been before carried out. We have analyzed mass media and scientific reports about algal outbreaks from 2016 to 2018, which allowed us to determine the geographical distribution of algal blooms in Russia, as well as the major effects of eutrophication. As a result, we showed that algal blooms happened in all major climate zones and all federal districts. Cyanobacteria are the most frequently reported photosynthetic organisms comprising algal blooms in freshwater reservoirs located in the continental part of Russia and in the Baltic Sea. Dinoflagellate dominated blooms are more characteristic for the coastal parts of the northeastern Pacific Ocean. The largest number of reports comes from the south of the European part of Russia. However, we did not find significant correlations between state statistics data on factors possibly affecting eutrophication (e.g., population, arable land area, fertilizers, livestock, air temperature, etc.) and the number of algal outbreaks in the regions. Mass media analysis showed that algal blooms attract considerable public attention in Russia, which requires the scientific community to actively participate in solving the problem.

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).

This article investigates the phase behavior of n-octacosane (C28H58) in the form of an aqueous dispersion with a particle size of about 100 nm. Samples of stable dispersions were prepared by ultrasonication without the addition of surfactants. Studies at various concentrations of n-alkane were performed by differential scanning calorimetry (DSC), powder X-ray diffraction, and light scattering methods. At low n-alkane concentrations, the sensitivity of DSC is not sufficient to detect the paraffin phase transitions. The light scattering method allows determining the phase transition temperatures (melting, crystallization, rotator phases) of n-alkane even in the 10−4 mass% dispersion.

Mesoporous CaCO3 crystals of sizes in the range 3–15 μm have attracted significant scientific attention as fully decomposable biocompatible drug delivery vectors. They are also used as sacrificial templates to produce polymer-based microcarriers (capsules, beads) and polymer scaffolds for tissue engineering at biologically friendly conditions. However, fabrication of CaCO3 crystals with the sizes beyond the conventional range without additives is still a challenge. There is a desperate need of sub-micrometre and sub-millimetre biocompatible and easily decomposable vectors for intracellular delivery and design of tailor-made polymer scaffolds, respectively. In this study, additive-free one-step fabrication of vaterite mesoporous crystals with sizes in the range from submicron (0.72 μm) up to tens of microns (55 μm) sizes is proposed. Crystals are grown by mixing of Ca2+ and CO32− salts in aqueous media. Internal structure and morphology of the crystals have been investigated. Encapsulation of lysozyme by means of co-synthesis shows an enhanced entrapment into submicron crystals. Besides, the approach to grow CaCO3 crystals on the surface of microcellulose ьш is demonstrated opening broad avenues for the development of vaterite coatings technologies.

Experimental results on the study of the regularity of isobutylene oligomerization at ultra-low temperatures (−195.8° C) in the presence of solid aluminum and zirconosilicate catalysts have been obtained for the first time. The maximum conversion in the oligomerization reaction of solid isobutylene at the boiling point of liquid nitrogen reached ≈ 90% in the case of an irradiated aluminosilicate catalyst. An increase in catalyst loading increases the selectivity for the yield of 2,3,3-trimethylpentene and 2,3,4-trimethylpentene dimers and reaches almost 99% for the most effective zeolite-aluminosilicate catalyst, eliminating the need for a distillation of the main product 2,3,4-trimethylpentene from the reaction mixtures. A study of the radiation-catalytic oligomerization of isobutylene was conducted. The optimal irradiation range of zeolites varies from 7.0 to 8.2 MRad, providing the isobutylene conversion above 95% due to an increase in the stability of excited active sites of the catalysts. Equations of experimental dependencies were created, based on the differential-integral approach to the analysis of the dependencies mentioned above. The numerical values of the constants in mathematical models of the isobutylene oligomerization reaction are computed. The results are explained considering the physical, molecular kinetic, and thermodynamic mechanisms of the process. The explanation of the mechanism of low-temperature oligomerization is presented by the generalized quantum–mechanical principle. The stepwise cyclic scheme of the catalytic oligomerization reaction is proposed.

A nanoarchitectural approach based on in situ formation of quantum dots (QDs) within/outside clay nanotubes was developed. Efficient and stable photocatalysts active under visible light were achieved with ruthenium-doped cadmium sulfide QDs templated on the surface of azine-modified halloysite nanotubes. The catalytic activity was tested in the hydrogen evolution reaction in aqueous electrolyte solutions under visible light. Ru doping enhanced the photocatalytic activity of CdS QDs thanks to better light absorption and electron-hole pair separation due to formation of a metal/semiconductor heterojunction. The S/Cd ratio was the major factor for the formation of stable nanoparticles on the surface of the azine-modified clay. A quantum yield of 9.3 % was reached by using Ru/CdS/halloysite containing 5.2 wt % of Cd doped with 0.1 wt % of Ru and an S/Cd ratio of unity. In vivo and in vitro studies on the CdS/halloysite hybrid demonstrated the absence of toxic effects in eukaryotic cells and nematodes in short-term tests, and thus they are promising photosensitive materials for multiple applications.

Bimetallic MnCo catalyst, supported on the mesoporous hierarchical MCM-41/halloysite nanotube composite, was synthesized for the first time and proved its efficacy in the selective oxidation of p-xylene to terephthalic acid under conditions of the AMOCO process. Quantitative yields of terephthalic acid were achieved within 3 h at 200–250 °C, 20 atm. of O2 and at a substrate to the Mn + Co ratio of 4–4.5 times higher than for traditional homogeneous system. The influence of temperature, oxygen, pressure and KBr addition on the catalyst activity was investigated, and the mechanism for the oxidation of p-toluic acid to terephthalic acid, excluding undesirable 4-carboxybenzaldehyde, was proposed.

The development of novel materials and approaches for effective energy consumption and the employment of renewable energy sources is one of the current trends in modern material science. With this respect, the number of researches is focused on the effective harvesting and storage of solar energy for various applications. Phase change materials (PCMs) are known to be able to store thermal energy of the sunlight due to adsorption and release of latent heat through reversible phase transitions. Therefore, PCMs are promising as functional additives to construction materials and paints for advanced thermoregulation in building and industry. However, bare PCMs have limited practical applications. Organic PCMs like paraffins suffer from material leakage when undergoing in a liquid state while inorganic ones like salt hydrates lack long-term stability after multiple phase transitions. To avoid this, the loading of PCMs in porous matrices are intensively studied along with the thermal properties of the resulted composites. The loading of PCMs in microcontainers of natural porous or layered clay materials appears as a simple and cost-effective method of encapsulation significantly improving the shape and cyclic stability of PCMs. Additionally, the inclusion of functional clay containers into construction materials allows for improving their mechanical and flame-retardant properties. This article summarizes the recent progress in the preparation of composites based on PCM-loaded clay microcontainers along with their future perspectives as functional additives in thermo-regulating materials.