Cobalt-Imidazole Complexes: Effect of Anion Nature on Thermochemical Properties.

A solvent-free method was proposed for the synthesis of hexaimidazolecobalt(II) nitrate and perchlorate complexes-[Co(CHN)](NO) and [Co(CHN)](ClO)-by adding cobalt salts to melted imidazole. The composition, charge state of the metal, and the structure of the resulting complexes were confirmed by elemental analysis, XPS, IR spectroscopy, and XRD. The study of the thermochemical properties of the synthesized complexes showed that [Co(CHN)](NO) and [Co(CHN)](ClO) are thermally stable up to 150 and 170 °C, respectively.

CO Methanation: Solvent-Free Synthesis of Nickel-Containing Catalysts from Complexes with Ethylenediamine.

CO methanation was studied in the presence of nickel catalysts obtained by the solid-state combustion method. Complexes with a varying number of ethylenediamine molecules in the coordination sphere of nickel were chosen as the precursors of the active component of the catalysts. Their synthesis was carried out without the use of solvents, which made it possible to avoid the stages of their separation from the solution and the utilization of waste liquids.

The Use of Hybrid Genetic Algorithm in the Kinetic Analysis of Thermal Decomposition of [Ni(CHN)](ClO) with Overlapping Stages.

This work describes the mathematical modeling of the thermal decomposition of the complex compound [Ni(En)](ClO) (En = CHN = 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.

New Solvent-Free Melting-Assisted Preparation of Energetic Compound of Nickel with Imidazole for Combustion Synthesis of Ni-Based Materials.

In this work two approaches to the synthesis of energetic complex compound Ni(Im)(NO) from imidazole and nicklel (II) nitrate were applied: a traditional synthesis from solution and a solvent-free melting-assisted method. According to infrared spectroscopy, X-ray diffraction, elemental and thermal analysis data, it was shown that the solvent-free melt synthesis is a faster, simpler and environmentally friendly method of Ni(Im)(NO) preparation. The results show that this compound is a promising precursor for the production of nanocrystalline Ni-NiO materials by air-assisted combustion method.

Catalytic Behavior of Iron-Containing Cubic Spinel in the Hydrolysis and Hydrothermolysis of Ammonia Borane.

The paper presents a comparative study of the activity of magnetite (FeO) and copper and cobalt ferrites with the structure of a cubic spinel synthesized by combustion of glycine-nitrate precursors in the reactions of ammonia borane (NHBH) hydrolysis and hydrothermolysis. It was shown that the use of copper ferrite in the studied reactions of NHBH dehydrogenation has the advantages of a high catalytic activity and the absence of an induction period in the H generation curve due to the activating action of copper on the reduction of iron. Two methods have been proposed to improve catalytic activity of FeO-based systems: (1) replacement of a portion of Fe cations in the spinel by active cations including Cu and (2) preparation of highly dispersed multiphase oxide systems, involving oxide of copper.

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 (LaMnO and LaCrO) 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).