K. V. Yusenko

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.

Syntheses of [Rh(NH3)5Cl][MCl6] (M = Re, Os, Ir) and Investigation of Their Thermolysis Products. Crystal Structure of [Rh(NH3)5Cl][OsCl6]

Binary complex salts [Rh(NH3)5Cl][MCl6], where M = Re, Os, Ir, have been synthesized and characterized. X-ray diffraction analysis indicated that the salts are isostructural. According to X-ray phase analysis, the products of their thermolysis in hydrogen are monophase stoichiometric nonequilibrium solid solutions Rh0.5M0.5 (M = Re, Os, Ir). The molecular and crystal structures of [Rh(NH3)5Cl][OsCl6] were determined in an X-ray structural analysis.

Synthesis, properties, and thermal decomposition products of [Ru(NH3)5Cl][PtCl6] and [Ru(NH3)5Cl]2[PtCl6]Cl2

The double complex salts [Ru(NH3)5Cl][PtCl6] (I) and [Ru(NH3)5Cl]2[PtCl6]Cl2 (II) were synthesized and studied by X-ray diffraction. They were found to be isostructural to the previously synthesized [Rh(NH3)5Cl][OsCl6] and [Ir(NH3)5Cl]2[PtCl6]Cl2. The thermolysis of the complexes in the atmosphere of hydrogen and helium was studied by the powder X-ray diffraction analysis. The product of the salt I thermolysis is a single-phase solid solution Ru0.5Pt0.5 (a = 3.857(3) Å), the thermolysis of salt II results in a double-phase metallic powder.

Double complex salts [Pt(NH3)5Cl][M(C2O4)3] · nH2O (M = Fe, Co, Cr): Synthesis and study

Double complexes [Pt(NH3)5Cl][Fe(C2O4)3] · 4H2O, [Pt(NH3)5Cl][Co(C2O4)3] · 2H2O, and [Pt(NH3)5Cl][Cr(C2O4)3] · 4H2O were synthesized and studied by single-crystal X-ray diffraction, X-ray phase analysis, differential thermal analysis, elemental analysis, and IR spectroscopy. The crystal structures of the compounds were examined from the viewpoint of the close packing of coordination polyhedra. The thermal properties of the synthesized complexes and K3[M(C2O4)3] salts (M = Fe, Co, Cr) were compared. A procedure for the synthesis of the FePt, CoPt, and CrPt intermetallic compounds through the thermolysis of the obtained complexes was developed.

Synthesis, Structure, and Thermal Decomposition of Chloropentamminerhodium(III) Hexabromoplatinate(IV)

The binary complex salt [Rh(NH3)5Cl][PtBr6] was synthesized and studied by X‐ray structural analysis. The crystallographic data are as follows: a = 12.013(2) Å, b = 8.401(2) Å, c = 15.999(3) Å, β = 91.13(3)°, V = 1614.3(6) Å3, space group P21/m, Z = 4, dx = 3.70 g/cm3, R = 0.086. The thermal decomposition of the salt in a hydrogen atmosphere is shown to produce a Rh0.5Pt0.5 solid solution with an FCC cell [a = 3.864(2) Å. The thermal decomposition of the salt in a helium atmosphere proceeds via the formation of metallic Pt and RhBr3 and finally results in a mixture of several solid solutions.

Solid solutions Ru x Ir1−x synthesized by thermolysis of coordination compounds

The double complex salts [Ir(NH3)5Cl][IrCl6], [Ru(NH3)5Cl][IrCl6], and [Ru(NH3)5Cl]2[IrCl6]Cl2 have been synthesized and characterized. An X-ray diffraction study demonstrated that these salts are isostructural with [Rh(NH3)5Cl][OsCl6] and [Ir(NH3)5Cl]2[PtCl6]Cl2 synthesized earlier. Thermolysis of these salts in hydrogen and helium has been studied. X-ray powder diffraction analysis show that thermolysis yields stoichiometric solid solutions of metals as the final products. The unit cell parameters of these products correspond to equilibrium phases.

Synthesis and characterization of [Co(NH3)5NO2][M(NO2)4] (M = Pt, Pd) compounds and their thermolysis products

Compounds [Co(NH3)5NO2][Pd(NO2)4] (I) and [Co(NH3)5NO2][Pt(NO2)4] · 1.5H2O (II) have been crystallized from solution. Their crystal structures have been solved, and thermolysis under various conditions studied. The thermolysis products are Co0.5M0.5 ordered solid solutions.

[Ru(NH3)6](MoO4)Cl·3H2O and [M(NH3)6](ReO4)3·2H2O (M = Ru, Ir). Synthesis and crystal structure

X-ray crystallographic analysis is used to determine the crystal structures of [Ru(NH3)6](MoO4)Cl·3H2O and [M(NH3)6](ReO4)3·2H2O (M = Ru, Ir) complex salts. The features of the fragment packing are studied.

Double complex salts with [Ru(NH3)5Cl]2+ cation and [OsCl6]2− anion: Synthesis and properties. Crystal structure of [Ru(NH3)5Cl]2[OsCl6]Cl2

Double complex salts [Ru(NH3)5Cl][OsCl6] and [Ru(NH3)5Cl]2[OsCl6]Cl2 were prepared and characterized. An X-ray diffraction study showed that [Ru(NH3)5Cl][OsCl6] is isostructural to the previously synthesized [Rh(NH3)5Cl][OsCl6]. The structure of [Ru(NH3)5Cl]2[OsCl6]Cl2 was solved by X-ray diffraction (a = 11.1849(8) Å, b = 7.9528(6) Å, c = 13.4122(9) Å; β = 99.765(2)°; V= 1175.75 Å3; space group C2/m; Z = 2). Thermolysis of the compounds under hydrogen and helium was studied. According to X-ray diffraction, nanosized metallic powders of the corresponding alloys are formed as the final products of thermolysis. The compositions of the obtained solid solutions are consistent with the phase diagram of the Ru-Os system.