Investigation of MFTIR infrared spectra of peat waxes with sorbed cationic surfactants

Journal of Applied Spectroscopy -     

Electron spin echo as a tool for investigation of surface structure of finely dispersed fractal solids

The ESE method was successfully used for investigating the texture of the adsorbents and catalysts. Equations were obtained for the kinetics of ESE signal decay due to dipole-dipole interaction between motionless paramagnetic centers distributed uniformly on the fractal surface of solid.

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, . , , .

     

Immobilized sol of cobalt(III) hydroxide as an efficient catalyst of water oxidation to dioxygen by the Ru(bpy)33+ complex

Catalysts of water oxidation to dioxygen by Ru(bpy) ₃ ³⁺ have been obtained by immobilization of colloidal Co(III) hydroxide on supports of the hydroxide types. These supports are found to be able either to enhance (Al(III), Bi(III), Sn(IV) and Ce(IV) hydroxides) or to weaken (Fe(III) and Mn(IV) hydroxides) the catalytic efficiency of the initial sol. The possible nature of the influence of the support is discussed.

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Ru(bpy) ₃ ³⁺ Co(III). - , ( Al(III), Bi(III), Sn(IV), Ce(IV)), ( Fe(III), Mn(IV)) . .

     

Selective water sorbents for multiple applications, 3. CaCl2 solution confined in micro- and mesoporous silica gels: Pore size effect on the “solidification-melting” diagram

In this communication we present a low-temperature “solidification-melting” phase diagram for CaCl₂/H₂O solutions confined in KSK and KSM silica gels. At salt concentrations of 0–48 wt. %, the diagram has been found to lie below the diagram reported for the bulk system by 15–30°C. It shows a depression of the solution melting point due to its confinment to the pores. Several other peculiarities of melting and solidification in this system are also reported and discussed. Beside fundamental interest, the data obtained could be of importance in many commercial areas such as refrigeration, accumulation of low temperature heat, frost prevention in building materials,etc.     

Hydrogen Production by Steam Reforming of Ethanol: A Two Step Process

A two-layer fixed-bed catalytic reactor for hydrogen production by steam reforming of ethanol is proposed. In this reactor ethanol is first converted to acetaldehyde over a Cu-based catalyst and then acetaldehyde is converted to a hydrogen-rich mixture over a Ni-based catalyst. It is shown that the use of such type of reactor prevents coke formation and provides hydrogen yields closed to equilibrium.     

Bismuth modified Pd/C as catalysts for hydrogen related reactions

The electrocatalytic activity of bimetallic BiPd catalysts supported on Sibunit carbon towards hydrogen oxidation/evolution reactions (HOR/HER) was studied in a gas diffusion electrode (GDE) setup. Catalysts were synthesized by deposition of Pd on the carbon support, followed by impregnation of Pd/C precursor with Bi(NO₃)₃ solution and reduction in hydrogen. Transmission electron microscopy and local EDX elemental analysis revealed that BiPd/C catalysts contain bimetallic particles with narrow size distribution with maxima at 3.2–4.1 nm. X-ray diffraction evidenced that bimetallic particles are constituted by Pd–Bi solid solution. It was shown that modification of Pd/C by bismuth increases the specific activity of palladium towards HOR/HER by a factor of 3.     

Determination of the activation energy of tuneling recombination for radiation-induced defects in CaO

Tunneling recombination between surface Fs_s ⁺- and bulk V^–-centers has been studied by ESR technique over the temperature range of 77–240 K. The activation energy has been measured.

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F_s ⁺- V^–- 77–240 .

     

Homogeneous catalysts for dioxygen evolution from water. Water oxidation by trisbipyridylruthenium(III) in the presence of cobalt, iron and copper complexes

Complexes of Co, Cu and Fe with bipyridyl, and cobalt complexes with ammonia, ethylenediamine and oxyacids are shown to be efficient catalysts for water oxidation by Ru(bpy) ₃ ³⁺ in both alkaline and weakly acidic media. Partially hydrolyzed forms of these complexes are assumed to be active.

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, Ru(bpy) ₃ ³⁺ , Co, Cu Fe, , . , .

     

New data on gas-phase radical reactions in the steam reforming of methane in the presence of catalysts: I. Nickel catalysts

Methane pyrolysis and steam reforming were studied over a series of nickel catalysts (Ni-Al₂O₃, Ni/MgO, and Ni/LiAlO₂) under the same conditions (650-750°C, P_CH4 = 0.001-0.03 MPa). Unlike heterogeneous reaction of pyrolysis, some of the steps of steam reforming of methane occur in the gas phase. When gasphase reactions were suppressed, the rate and activation energy of steam reforming are close to the corresponding kinetic characteristics for pyrolysis. Hypothetically, the rate-limiting step of the process is the dissociative adsorption of methane on nickel in this case.