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
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 using ICP-OES, XRD, XPS, SEM, TEM, HRTEM. TEM/EDX, mid-IR, far-IR spectroscopes. and N-2-adsorption/desorption technique The results of the multipiong analysis reveal the formation of osmium(0) nanoclusters within the cavities of zeolite-Y without causing alteration in the framework lattice, formation of mesopores. or loss in the crystallinity of the host material More importantly. far-IR studies showed that after the reduction of Os3+ canons by sodium borohydride the Na+ canons reoccupy their authentic canon sites restoring the integrity of zeolite-Y The catalytic activity of osmium(0) nanoclusters stabilized by zeolite framework was tested in the aerobic oxidation of activated. unactivated and heteroatom containing alcohols to carbonyl compounds and was found to provide high activity and selectivity even under mild conditions (80 degrees C and 1 atm O-2 or air) Moreover, they were found to be stable enough to be isolated and bottled as solid material, which can be reused as active catalyst under the identical conditions of the first run


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Çelik, Derya; Özkar, Saim; Department of Chemistry (2012)
This dissertation presents the preparation and characterization of rhodium(0) nanoparticles supported on hydroxyapatite, and investigation of their catalytic activity in hydrogen generation from the hydrolysis of hydrazine-borane and ammonia-borane. Rh+3 ions were impregnated on hydroxyapatite by ion-exchange; then rhodium(0) nanoparticles supported on hydroxyapatite were formed in-situ during the hydrolysis of hydrazine-borane at room temperature. The rhodium(0) nanoparticles supported on hydroxyapatite we...
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Demir, Ayhan Sıtkı; Sesenoglu, O; Aksoy-Cam, H; Kaya, H; Aydogan, K (Elsevier BV, 2003-05-16)
The selective conversion of 1-(2-furyl)-2-hydroxyethan-1-one and ethyl 2-(2-furyl)-2-oxo acetate into (E)- and (Z)-oximes and oxime ethers followed by oxazaborolidine-catalyzed enantioselective reduction using different amino alcohols furnished both enantiomers of the important chiral building block 2-amino-2-(2-furyl)ethan-1-ol with an ee of up to 96%.
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Akbayrak, Serdar; Özkar, Saim (Royal Society of Chemistry (RSC), 2014-01-01)
Ruthenium(0) nanoparticles supported on xonotlite nanowire (Ru(0)@X-NW) were prepared by the ion exchange of Ru3+ ions with Ca2+ ions in the lattice of xonotlite nanowire followed by their reduction with sodium borohydride in aqueous solution at room temperature. Ru(0)@X-NW were characterized by a combination of advanced analytical techniques. The results show that (i) highly dispersed ruthenium(0) nanoparticles of 4.4 +/- 0.4 nm size were formed on the surface of xonotlite nanowire, (ii) Ru(0)@X-NW show hi...
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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...
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Genişel, Mustafa Fatih; Yılmaz, Ayşen; Department of Chemistry (2005)
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 disadvantag...
Citation Formats
M. Zahmakiran, S. Akbayrak, T. Kodaira, and S. Özkar, “Osmium(0) nanoclusters stabilized by zeolite framework; highly active catalyst in the aerobic oxidation of alcohols under mild conditions,” DALTON TRANSACTIONS, pp. 7521–7527, 2010, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/69917.