Разработка методики синтеза наноразмерных частиц металлов платиновой группы на поверхности носителя с целью создания катализаторов для портативных генераторов водорода на основе гидролиза боргидрида натрия.

The reaction properties of supported rhodium nanoparticles depend on degree of interaction between rhodium chloride and support at the stage of preparation Rh/TiO2 catalysts. Their catalytic properties are defined by its calcinations temperature and presence of impurity on support surfaceРазработаны научные основы направленного синтеза активных и стабильных катализаторов для портативных генераторов водорода. Выполнены исследования Rh/TiO2 катализаторов и испытания их в реакции гидролиза боргидрида натрия

Development of synthesis of supported noble metal nanoparticles for preparation of catalysts used in portable hydrogen generators based on sodium borohydride hydrolysis

The reaction properties of supported rhodium nanoparticles depend on degree of interaction between rhodium chloride and support at the stage of preparation Rh/TiO2 catalysts. Their catalytic properties are defined by its calcinations temperature and presence of impurity on support surfac

The Formation of Perovskite during the Combustion of an Energy-Rich Glycine–Nitrate Precursor

The effect of different regimes of combustion of glycine–nitrate precursors on the formation of perovskite phases (LaMnO3 and LaCrO3) without additional heat treatment was studied. The following three combustion regimes were compared: the traditional solution combustion synthesis (SCS), volume combustion synthesis (VCS) using a powdered precursor, and self-propagating high-temperature synthesis (SHS) using a precursor pellet. The products of combustion were studied using a series of physicochemical methods (attenuated total reflection infrared spectroscopy (ATR FTIR), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and thermal analysis). SHS was found to be the most productive regime for the formation of perovskite because of its ability to develop high temperatures in the reaction zone, which led to a reduced content of the thermally stable lanthanum carbonate impurities and to an increased yield and crystallite size of the perovskite phase. The reasons for the better crystallinity and purity of LaCrO3 as compared with LaMnO3 is also discussed, namely the low temperatures of the onset of the thermolysis, the fast rate of combustion, and the favorable thermodynamics for the achievement of high temperatures in the reaction zone

Solid-State NaBH₄/Co Composite as Hydrogen Storage Material: Effect of the Pressing Pressure on Hydrogen Generation Rate

A solid-state NaBH4/Co composite has been employed as a hydrogen-generating material, as an alternative to sodium borohydride solutions, in the long storage of hydrogen. Hydrogen generation begins in the presence of cobalt-based catalysts, immediately after water is added to a NaBH4/Co composite, as a result of sodium borohydride hydrolysis. The hydrogen generation rate has been investigated as a function of the pressure used to press hydrogen-generating composites from a mechanical mixture of the hydride and cobalt chloride hexahydrate. The hydrogen generation rate was observed to increase with the increase of this pressure. Pre-reduction of the cobalt chloride, using a sodium borohydride solution, leveled this dependence with a two-fold decrease in the gas generation rate. According to TEM and XPS data, oxidation of the particles of the pre-reduced cobalt catalyst took place during preparation of the composites, and it is this oxidation that appears to be the main reason for its low activity in sodium borohydride hydrolysis

Water purification from chlorobenzenes using heteroatom functionalized carbon nanofibers produced on self organizing Ni Pd catalyst

The development of effective methods for the processing of hazardous wastes containing chlorinated hydrocarbons still remains a big challenge. Herein, the approach allowing the transformation of chlorohydrocarbons into functionalized carbon nanomaterials was demonstrated for 1,2 dichloroethane DCE used as a model compound. Carbon nanofibers CNF doped with nitrogen and oxygen heteroatoms were fabricated by a joint decomposition of DCE and co reagent CH3CN, NH4OH, C2H5OH, and H2O . The Ni Pd 5 alloy was used as a catalyst precursor for the CNF synthesis. Pristine Ni Pd alloy was found to undergo disintegration under the reaction conditions and to induce an active growth of the functionalized carbon nanofibers. The obtained CNF were shown to have a similar segmental structure of carbon filaments and to possess high specific surface area up to 470 m2 g and porosity up to 0.9 cm3 g . According to X ray photoelectron spectroscopy data, the nitrogen content within CNF samples prepared using N comprising precursors was about 1.0 1.7 at . The total oxygen content reaches 3.6 at . The obtained materials were demonstrated to be attractive for the dichlorobenzene adsorption from its aqueous solution

The Use of Hybrid Genetic Algorithm in the Kinetic Analysis of Thermal Decomposition of [Ni(C₂H₈N₂)₃](ClO₄)₂ with Overlapping Stages

This work describes the mathematical modeling of the thermal decomposition of the complex compound [Ni(En)3](ClO4)2 (En = C2H8N2 = ethylenediamine) in an inert atmosphere under non-isothermal conditions. This process is characterized by several simultaneous and intense stages: elimination of ethylenediamine from the nickel coordination sphere, decomposition of perchlorate anions, and explosive-like oxidation of free or bound ethylenediamine. These stages overlap and merge into a one step on the differential thermogravimetric curve. Typically, this curve is modeled as a one-stage process during kinetic analysis. In this paper, for the first time, the data from the dynamic mass-spectral thermal analysis and thermogravimetric analysis were modeled using the hybrid genetic algorithm, and the results were compared. A two-stage scheme of [Ni(En)3](ClO4)2 thermolysis was proposed and the kinetic parameters for each stage were obtained. It was shown that the decomposition of [Ni(En)3](ClO4)2 begins with the elimination of one molecule of ethylenediamine (stage A), then the perchlorate anions quickly decompose with the evolution of oxygen (stage B). We believe that the resulting ClO4−x− (x = 1–3), as stronger oxidizing agents, instantly start an explosive-like exothermic process of ethylenediamine oxidation (stage B)