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

Download

index.pdf

Date

2010

Author

Erdoğan, Huriye

Metadata

Show full item record

Item Usage Stats

189
views

67
downloads

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 present in the composition (e.g., chemical hydrides). The latter option seems to be the most promising since it permits a higher mass ratio of hydrogen. Recently, ammonia-borane complex (NH3BH3, AB) has been considered as solid hydrogen storage material since it possess one of the highest hydrogen contents (19.6 wt. %) and high stability under the moderate conditions. Hydrolysis and methanolysis are the two reactions liberating hydrogen from AB. However, a catalyst is needed for hydrogen generation from methanolysis of AB. In this context, we aim to develop PVP-stabilized palladium(0) and ruthenium(0) nanoclusters as catalyst for the methanolysis of AB. The PVP-stabilized palladium(0) and ruthenium(0) nanoclusters were prepared from the in-situ reduction of palladium(II) acetylacetonate and ruthenium(III) chloride respectively in the methanolysis of AB. The prepared palladium(0) nanoclusters were isolated as solid materials by removing the volatile in vacuum and characterized by using TEM, SAED, XPS, FT-IR, XRD and UV-visible electronic absorption spectroscopy techniques while and ruthenium(0) nanoclusters were characterized by TEM, XPS, XRD, FT-IR and UV-visible electronic absorption spectroscopy techniques. The kinetics of methanolysis of AB catalyzed by palladium(0) and ruthenium(0) nanoclusters were studied depending on the catalyst concentration, substrate concentration and temperature. The activation parameters of the catalytic methanolysis reaction obtained from the evaluation of kinetic data.

Subject Keywords

Chemistry.

URI

http://etd.lib.metu.edu.tr/upload/3/12611847/index.pdf
https://hdl.handle.net/11511/19599

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

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...
Effect of stabilizer on the catalytic activity of Kobalt(0) Nanoclusters catalyst in the hydrolysis of Sodium Borohydride Koçak, Ebru; Özkar, Saim; Department of Chemistry (2009) 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 ...
Preparation and characterization of zeolite confined cobalt(0) nanoclusters as catalyst for hydrogen generation from the hydrolysis of sodium borohydride and ammonia borane Rakap, Murat; Özkar, Saim; Department of Chemistry (2011) Because of the growing concerns over the depletion of fossil fuel supplies, environmental pollution and global warming caused by a steep increase in carbon dioxide and other greenhouse gases in the atmosphere, much attention has been given to the development of renewable energy sources that are the only long-term solution to the energy requirements of the world’s population, on the way towards a sustainable energy future. Hydrogen has been considered as a clean and environmentally benign new energy carrier ...
Determination of thallium by volatile compound generation atomic absorption spectrometry Ataman, Seval; Ataman, Osman Yavuz; Department of Chemistry (2011) Determination of thallium is important due to its toxic effects on the environment and human health. Extremely low abundance of thallium in earth crust requires very sensitive and accurate methods for determination of this element. Although volatile compound generation is a sensitive, fast and economical method, thallium determination by this method has not been sufficiently investigated in literature, because of the fact that the formation of volatile forms of this element is a difficult task. A continuous...
Dimethyl Ether (DME) synthesis using mesoporous SAPO-34 like catalytic materials Demir, Hakan; Sezgi, Naime Aslı; Doğu, Timur; Department of Chemical Engineering (2011) In 21st century, researchers make great effort of finding a clean transportation fuel to diminish the severe effects of conventional transportation fuel combustion such as global warming and air pollution. Dimethyl ether is considered as a strong fuel alternative due to its good burning characteristics and environmentally friendly properties. In order to produce dimethyl ether, different synthesis routes and solid acid catalysts are being utilized. SAPO-34 is an aluminophosphate based catalyst having modera...

Citation Formats

H. Erdoğan, “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,” M.S. - Master of Science, Middle East Technical University, 2010.