Co-Pt bimetallic catalysts for the selective oxidation of carbon monoxide in hydrogen-containing mixtures

The performance of a Co-Pt powder and of Co-Pt catalysts supported on γ-Al₂O₃ and on the graphite-like carbon material Sibunit in selective CO oxidation in hydrogen-containing mixtures is considered. Fine particles of metal-metal solid solutions and intermetallides were obtained by the decomposition of a Co- and Pt-containing double complex salt in a hydrogen atmosphere at ～400°C. As compared to their Pt and Co monometallic counterparts, the bimetallic catalysts are more active and allow the CO concentration in hydrogen-containing mixtures to be reduced from 1 to 10^?3 vol %. This effect is likely due to the formation of bimetallic particles of a Co-Pt solid solution on the support surface.     

SYNTHESIS,STRUCTURE, AND THERMAL PROPERTIES OF DOUBLE COMPLEX SALTS AS PRECURSORS OF NANOALLOYS OF IMMISCIBLE METALS

Journal of Structural Chemistry - We report results of structural studies of multicomponent compounds, double complex salts, used as predecessors of nanoalloys of immiscible metals in Rh–Pd,...     

Nuclear spin nanomagnet in an optically excited quantum dot

Linearly polarized light tuned slightly below the optical transition of the negatively charged exciton (trion) in a single quantum dot causes the spontaneous nuclear spin polarization (self-polarization) at a level close to 100%. The effective magnetic field of spin-polarized nuclei shifts the optical transition energy close to resonance with photon energy. The resonantly enhanced Overhauser effect sustains the stability of the nuclear self-polarization even in the absence of spin polarization of the quantum dot electron. As a result the optically selected single quantum dot represents a tiny magnet with the ferromagnetic ordering of nuclear spins-the nuclear spin nanomagnet.     

Cryogenic technologies for preparation of hydrocarbon products and helium from associated petroleum gases

Cryogenic technologies for combined extraction of commercial products, including helium, from associated petroleum gases with minimum energy costs and capital investments were described. The Geliimash Scientific and Production Association, Open Joint-Stock Company, undertakes the manufacture of the whole range of equipment for these technologies.     

Crystal structure of Cs8[α-BW12O40][RhCl6]·5·5H2O double salt

By heating in the air [HBW₁₁O₃₉]⁸⁻ with [Rh₂(CH₃COO)₄(H₂O)₂] in the excess of tungstate followed by crystallization in the presence of CsCl, a double salt of Cs₈[6h-BW₁₂O₄₀][RhCl₆]·5.5H₂O is obtained and structurally characterized. Its crystal structure is determined by single crystal X-ray diffraction. The structure is ionic with Cs⁺ cations, [BW₁₂O₄₀]⁵ anions with the Keggin structure, and [RhCl₆]³ octahedral anions.     

Complex salts trans-[Rh(β-Pic)4Cl2]X (X = Cl?, ReO 4? , and ClO 4? ): Synthesis, crystal structures, and thermal properties

Three novel complex salts containing the cation trans-[Rh(β-Pic)₄Cl₂]⁺ with the anions Cl⁻ (I), ReO₄⁻ (II), and ClO₄⁻ (III) were obtained and characterized by elemental analysis, X-ray diffraction, NMR spectroscopy, and IR spectroscopy. The complex trans-[Rh(β-Pic)₄Cl₂]ReO₄ crystallizes from DMF as a solvate in which solvent molecules fill the channels formed by the cations and anions. The thermal properties of complexes I, II, and II · DMF were examined by DTA. Final and some intermediate products of the thermolysis were isolated and characterized by physicochemical methods.