Oxidative dehydrogenation of 2,3,5-trimethyl-1,4-hydroquinone in the presence of titanium dioxide hydrogel

Liquid-phase oxidative dehydrogenation of 2,3,5-trimethyl-1,4-hydroquinone in the presence of titanium dioxide hydrogel was studied by a kinetic method. Associative interactions between the substrate, oxidant, and gel were detected by voltammetry and ESR and IR spectroscopy.Russian Foundation for Basic Researc

Synthesis of double oxides TiO2-SiO2 with low titanium content by hydrolysis of tetrabutoxytitanium-tetraethoxysilane mixture in an atmosphere of water vapor and ammonia

A series of TiO2-SiO2 binary xerogels with the titanium content lower than 7 mol % were prepared by joint hydrolysis of tetrabutoxytitanium and tetraethoxysilane in a desiccator in the atmosphere of vapor over 5% aqueous NH3 solution under static conditions. The physicochemical properties of the material were examined by IR spectroscopy and by the kinetic method with hydrogen peroxide decomposition as model reaction. © 2013 Pleiades Publishing, Ltd

Synthesis of Cu(II)-containing TiO2-SiO2 binary xerogels by hydrolysis of a mixture of tetrabutoxytitanium, tetraethoxysilane, and copper(II) chloride in a water-ammonia atmosphere

A Cu(II)-containing binary xerogel TiO2-SiO2 was synthesized by joint hydrolysis of tetrabutoxytitanium, teraethoxysilane and copper(II) chloride dissolved in their mixture. The synthesis was performed in a vapor of 10% aqueous ammonia under static conditions. EPR spectroscopy was used to examine the state of Cu(II) in the xerogel matrix. Data on specific features of the behavior of saccharose within xerogel pores under heating were obtained. The catalytic activity of the xerogel was tested by the kinetic method on model reactions of hydrogen peroxide decomposition and oxidative dehydrogenation of trimethylhydroquinone. © 2013 Pleiades Publishing, Ltd

Synthesis in a gel and sorption properties of N-2-sulfoethyl chitosan

A new procedure was developed for preparation of chelate amino-containing polymer N-2-sulfoethyl chitosan by synthesis in a gel through the reaction between chitosan and sodium 2-bromoethanesulfonate, yielding a polymer with the degree of substitution of up to 0.5. The structure of the resulting polymers was confirmed by 1H NMR spectroscopy. The sorption characteristics with respect to transition and alkaline-earth metal ions were determined for the cross-linked polymers. © 2013 Pleiades Publishing, Ltd

Synthesis of spherical TiO<inf>2</inf>-SiO<inf>2</inf> granules by joint hydrolysis of tetrabutoxytitanium and tetraethoxysilane, with KU-23 polymeric cation exchanger used as matrix

Joint hydrolysis of tetrabutoxytitanium and tetraethoxysilane in a desiccator in the presence of water vapor was used to synthesize spherical granules of a TiO2-SiO2 binary xerogel with a KU-23 polymeric cation exchanger used as a matrix. Specific structural features of the resulting new form of the catalytic system were revealed. It was shown that the catalytic activity of titanium contained in the Ti-O-Si mixed amorphous phase substantially exceeds that of TiO2 in the anatase phase. © Pleiades Publishing, Ltd., 2014. Original Russian Text © A.B. Shishmakov, O.V. Koryakova, Yu.V. Mikushina, D.O. Antonov, L.A. Petrov, 2014

Synthesis of ZrO2–SiO2 and ZrO2–SiO2–Cu(II) xerogels by joint hydrolysis in an aqueous ammonia atmosphere

ZrO2–SiO2 xerogels have been synthesized through hydrolysis of a mixture of tetrabutoxyzirconium and tetraethoxysilane in a desiccator in a vapor of a 15% aqueous NH3 atmosphere. ZrO2–SiO2–Cu(II) xerogels were synthethized analogously through joint hydrolysis of a mixture of the organometallic precursors and copper(II) chloride. The effect of synthesis conditions on the physical and chemical properties of the resulting material has been studied. © 2016, Pleiades Publishing, Ltd

Synthesis of TiO2-SiO2 and TiO2-SiO 2-Cu(II) xerogels by cohydrolysis of precursors in the absence of a solvent and redox catalysts

Cohydrolysis of tetrabutoxytitanium and tetraethoxysilane in a desiccator in the presence of water vapor produced a TiO2-SiO2 binary xerogel and its Cu(II)-containing analog. The hydrolysis was performed without using either a solvent, or redox catalysts. The effect of the synthesis conditions on the physicochemical properties of the obtained material was studied. © 2014 Pleiades Publishing, Ltd