Synthesis of Ti,Cr,Mn,Fe,Co,Ni,Cu,Zn sulfide by solid-gas reactions,investigation of structural and conducting properties

Genişel, Mustafa Fatih
In this study some of the first row transition metal oxides were transformed to metal sulfides by new solid gas reaction system. Transition metal sulfides have wide application area in industry and technology. Several techniques are known for the production of metal sulfides. Such as reactions between metal or metal oxide with H2S, precipitation in several liquid medium, reaction between metal and sulfur in closed vessel, chemical vapor deposition (CVD) technique. These techniques will have some disadvantages; for example, reactants are rarely available or expensive materials, their production systems are complicated and hard to set up these systems, products contain oxygen or hydrogen or corresponding metal sulfate as impurities. In our new sulfidizing system the reactants are metal oxides, carbon and SO2. These materials can be found easily. Especially, SO2 usage in this system is a big advantage of giving possibility of usage the hazardous waste product of SO2 in industry. The sulfidizing gas mixture was obtained by passing SO2 over activated carbon at 750 OC in a vertical tubular furnace. The obtained gas contains, mainly, CS2, CO and COS. The sulfidizing reactions took place in the horizontal tubular furnace at 450OC-1250 OC. The duration of the reaction, (three hours), and flow rate (60ml/min) of the SO2 gas were kept constant. The products were examined by X-ray powder diffraction and Raman scattering spectroscopy. All examined metal oxides were transformed to metal sulfides by sulfidizing gas mixture successfully. Ti3S5 was obtained from TiO2. Cr2S3 was obtained from Cr2O3. MnS (Alabandite) was obtained from MnO2. FeS and Fe1-xS (Pyrrhotite) were obtained from Fe2O3. Co9S8 (Cobaltpentlandite) and CoS (Jaipurite) were obtained from Co3O4. NiS was obtained from NiO. Cu7.2S, Cu1.6S (Calcocite-Q), Cu1.81S, Cu7S4 (Anilite) Cu9S5 (Digenite), Cu8S5 (Geerite) were


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Alper, Fatma; Özkar, Saim; Department of Chemistry (2004)
In this study, the effect of a donor ligand on the stabilization of a carbonyl pyrazine tungsten complex was studied. The pentacarbonylpyrazinetungsten(0) complex could be formed from the photolysis of hexacarbonyltungsten(0) in the presence of pyrazine and could be isolated as crystalline solid. However, the complex was found to be unstable in solution, being converted to a bimetallic complex, (CO)5W(pyz)W(CO)5 and free pyrazine molecule. Two complexes exist in solution at equilibrium. The equilibrium cons...
Synthesis of ferrocenyl pyrazoles by the reaction of (2-formyl-1-chlorovinyl)ferrocene with hydrazines
Zora, Metin (Elsevier BV, 2007-10-15)
Synthesis of ferrocenyl-substituted pyrazoles via the reaction between (2-formyl-1-chlorovinyl)ferrocene and hydrazine derivatives is described. Depending upon the substitution pattern of hydrazine, the reaction affords 1-alkyl/aryl-5-ferrocenylpyrazoles and/or 1-alkyl/ aryl-3-ferrocenylpyrazoles. The reaction appears to be general for a variety of hydrazine derivatives.
Synthesis and characterization of ruthenium(0) metal nanoparticles as catalyst in the hydrolysis of sodium borohydride
Zahmakıran, Mehmet; Özkar, Saim; Department of Chemistry (2005)
Sodium borohydride is stable in alkaline solution, however, it hydrolyses and generates hydrogen gas in the presence of suitable catalyst. By this way hydrogen can be generated safely for the fuel cells. All of the catalyst having been used in the hydrolysis of sodium borohydride, with one exception, are heterogeneous. The limited surface area of the heterogeneous and therefore, have limited activity because of the surface area. Thus, the use of metal nanoclusters as catalyst with large surface area is expe...
Optical and Vibrational Properties of [Pt@Pb-12](2-), [Ni@Pb-12](2-), and [Ni@Pb-10](2-) Zintl Ion Clusters
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The optical and vibrational properties of Pt- and Ni-centered Pb-Zintl-ion clusters have been investigated by UV/Vis and FTIR spectroscopy. Computational studies have been performed to better interpret the experimental data, due to a lack of any FTIR and UV/Vis spectroscopic studies on these clusters or similar ones in the literature. UV/Vis spectroscopic analyses show an asymmetric broad absorption band, with a maximum at 265 nm for both Pt- and Ni-centered Pb clusters. FTIR spectroscopic analysis demonstr...
Osmium(0) nanoclusters stabilized by zeolite framework; highly active catalyst in the aerobic oxidation of alcohols under mild conditions
Zahmakiran, Mehmet; Akbayrak, Serdar; Kodaira, Tetsuya; Özkar, Saim (Royal Society of Chemistry (RSC), 2010-08-01)
Osmium(0) nanoclusters stabilized by zeolite-Y framework were reproducibly prepared by a simple two step procedure involving the incorporation of osmium(III) canons into the zeolite matrix by ion-exchange, followed by their reduction within the cavities of zeolite with sodium borohydride in aqueous solution all at room temperature. The composition and morphology of osmium(0) nanoclusters stabilized by zeolite framework, as well as the integrity and crystallinity of the host material were investigated by usi...
Citation Formats
M. F. Genişel, “Synthesis of Ti,Cr,Mn,Fe,Co,Ni,Cu,Zn sulfide by solid-gas reactions,investigation of structural and conducting properties,” M.S. - Master of Science, Middle East Technical University, 2005.