Effect of stabilizer on the catalytic activity of Kobalt(0) Nanoclusters catalyst in the hydrolysis of Sodium Borohydride

Download

index.pdf

Date

2009

Author

Koçak, Ebru

Metadata

Show full item record

Item Usage Stats

244
views

105
downloads

The development of new storage materials will facilitate the use of hydrogen as a major energy carrier in near future. Among the chemical hydrides used as hydrogen storage materials for supplying hydrogen at ambient temperature, sodium borohydride seems to be an ideal one because it is stable under ordinary conditions and liberates hydrogen gas in a safe and controllable way in aqueous solutions. However, self hydrolysis of sodium borohydride is so slow that requires a suitable catalyst. This work aims the use of water dispersible cobalt(0) nanoclusters having large portion of atoms on the surface as catalyst for the hydrolysis of sodium borohydride. In-situ formation of cobalt(0) nanoclusters and catalytic hydrolysis of sodium borohydride were performed starting with a cobalt(II) chloride as precursor and sodium borohydride as reducing agent and substrate in the presence of a water soluble stabilizer. As stabilizer, water soluble polyacrylic acid as well as hydrogen phosphate ion were tested. Cobalt(0) nanoclusters were characterized by using all the available analytical methods including FT-IR, TEM, XPS, UV-visible electronic absorption spectroscopy. The kinetics of cobalt(0) nanoclusters catalyzed hydrolysis of sodium borohydride were studied depending on the catalyst concentration, substrate concentration, stabilizing agent concentration and temperature.

Subject Keywords

Chemistry.

URI

http://etd.lib.metu.edu.tr/upload/3/12611280/index.pdf
https://hdl.handle.net/11511/19169

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Synthesis and characterization of hydrogenphophate-stabilized nizkel(0) nanoclusters as catalyst for the hydrolysis of sodium borohydride Metin, Önder; Özkar, Saim; Department of Chemistry (2006) The development of new storage materials will facilitate the use of hydrogen as a major energy carrier in near future. In hydrogen economy, chemical hydrides such as NaBH4, KBH4, LiH, NaH have been tested as hydrogen storage materials for supplying hydrogen at ambient temperature. Among these chemical hydrides, sodium borohydride seems to be an ideal hydrogen storage material because it is stable under ordinary conditions and liberates hydrogen gas in a safe and controllable way in aqueous solutions. Howeve...
Water dispersible acetate stabilized ruthenium(0) nanoclusters as catalyst for hydrogen generation from the hydrolysis of sodium borohyride Zahmakiran, Mehmet; Özkar, Saim (Elsevier BV, 2006-10-02) The development of new storage materials will facilitate the use of hydrogen as a major energy vector in near future. In the hydrogen economy, chemical hydrides such as NaBH4, KBH4, LiH, NaH have been tested as precursor materials for supplying hydrogen at ambient temperature. Among these chemical hydrides, sodium borohydride (NaBH4) provides a safe and practical mean of producing hydrogen. Sodium borohydride is stable in basic solution; however, hydrolysis generates hydrogen gas in the presence of a suitab...
The preparation and characterization of zeolite confined rhodium(0) nanoclusters: a heterogeneous catalyst for the hydrogen generation from the methanolysis of ammonia-borane Çalışkan, Salim; Özkar, Saim; Department of Chemistry (2010) Among the new hydrogen storage materials, ammonia borane (AB) appears to be the most promising one as it has high hydrogen content, high stability, and being environmentally benign. Dehydrogenation of AB can be achieved via hydrolysis, thermolysis or methanolysis. Methanolysis of AB eliminates some drawbacks of other dehydrogenation reactions of AB. The use of colloidal and supported particles as more active catalyst than their bulky counterparts for the hydrolysis of AB implies that reducing the particle s...
In-situ generation of poly(n-vinyl-2-pyrrolidone)-stabilized palladium(0) and ruthenium(0) nanoclusters as catalysts for hydrogen generation from the methanolysis of ammonia-borane Erdoğan, Huriye; Özkar, Saim; Department of Chemistry (2010) More attention has been paid to find new type renewable energy sources because of increasing concern about the environmental problems arising from the combustion of fossil fuels as energy sources. The development of new storage materials will facilitate the use of hydrogen as a major energy carrier. Several possibilities exist for ‘‘solid-state’’ storage: the hydrogen can be trapped in metal organic frameworks, carbon nanotubes and certain alloys; or one can use materials in which hydrogen is already presen...
Electrochromic and photovoltaic applications of benzotriazole bearing donor acceptor type conjugated polymers Baran, Derya; Toppare, Levent Kamil; Department of Chemistry (2010) Organic semi-conductors are of great interest since these compounds can be utilized as active layers in many device applications such as ECDs, LEDs and solar cells. Incorporating the benzotriazole units into the polymer backbone enhances the optical properties of donor units. Hexyl thiophene and pyrrole are commonly used as electron donor materials. Benzotriazole can be coupled to hexyl thiophene or pyrrole to yield materials which can be polymerized to give donor acceptor type polymers. These materials are...

Citation Formats

E. Koçak, “Effect of stabilizer on the catalytic activity of Kobalt(0) Nanoclusters catalyst in the hydrolysis of Sodium Borohydride,” M.S. - Master of Science, Middle East Technical University, 2009.