Temel prensipler yöntemiyle magnezyum ve demir - titanyum hidrürlerinin modellenmesi, tasarımı ve üretimi

Download

T0RJNU1EQT0.pdf

Date

2008

Author

Aydınol, Kadri M.
Tan, Serdar
Akyıldız, Hasan
Kınacı, Alper
Şen, Fatih

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

92
views

154
downloads

A candidate hydrogen storing material should have high storage capacity and fast dehydrogenation kinetics. On this basis, magnesium hydride (MgH2) is an outstanding compound with 7.66 wt % storage capacity, despite its slow dehydriding kinetics and high desorption temperature. Therefore in this study, bulk and surface alloys of Mg with improved hydrogen desorption characteristics were investigated. In this respect, formation energies of alloyed bulk MgH2 as well as the adsorption energies on alloyed magnesium (Mg) and MgH2 surface structures were calculated by total energy pseudopotential methods. Furthermore, the effect of substitutionally placed dopants on the dissociation of hydrogen molecule (H2) at the surface of Mg was studied via Molecular Dynamics (MD). The results displayed that 31 out of 32 selected dopants contributed to the decrease in formation energy of MgH2 within a range of ~ 37 kJ/mol-H2 where only Sr did not exhibit any such effect. The most favorable elements in this respect came out to be; P, K, Tl, Si, Sn, Ag, Pb, Au, Na, Mo, Ge and In. Afterwards, a systematical study within adsorption characteristics of hydrogen on alloyed Mg surfaces (via dynamic calculations) as well as calculations regarding adsorption energies of the impurity elements were performed. Accordingly, Mo and Ni yielded lower adsorption energies; -9.2626 and -5.2995 eV for substitutionally alloyed surfaces, respectively. MD simulations presented that Co is found to have a splitting effect on H2 in 50 fs, where the first hydrogen atom is immediately adsorbed on Mg substrate. Finally, charge density distributions were realized to verify the distinguished effects of most 3d and 4d transition metals in terms of their catalyzer effects. 7 In experimental studies, the FeTi compound was produced by the electrodeoxidation method. In addition, the catalyzer effect of Co in the hdriding of magnesium was investigated in thin film form.

Subject Keywords

Magnesium Hydride, Hydrogen Storage, First Principles, Molecular Dynamics, Surface Adsorption

URI

https://app.trdizin.gov.tr/publication/project/detail/T0RJNU1EQT0
https://hdl.handle.net/11511/49931

Collections

Department of Metallurgical and Materials Engineering, Project and Design

Suggestions

OpenMETU
Core

Ab initio design of novel magnesium alloys for hydrogen storage Keçik, Deniz; Aydınol, Mehmet Kadri; Department of Metallurgical and Materials Engineering (2008) A candidate hydrogen storing material should have high storage capacity and fast dehydrogenation kinetics. On this basis, magnesium hydride (MgH2) is an outstanding compound with 7.66 wt % storage capacity, despite its slow dehydriding kinetics and high desorption temperature. Therefore in this study, bulk and surface alloys of Mg with improved hydrogen desorption characteristics were investigated. In this respect, formation energies of alloyed bulk MgH2 as well as the adsorption energies on alloyed magnesi...
Ab initio alloying of Mg for hydrogen storage Kecik, Deniz; Aydınol, Mehmet Kadri (null; 2008-12-01) A candidate hydrogen storing material should have high storage capacity and fast dehydrogenation kinetics. On this basis, magnesium hydride (MgH 2) is an outstanding compound with 7.6 wt % storage capacity, despite its slow dehydriding kinetics and high desorption temperature. Therefore in this study, formation energies of alloyed bulk MgH2, adsorption energies on alloyed magnesium (Mg) and MgH2 surface structures were calculated by total energy pseudopotential methods. Also, the effect of substitutionally ...
Induction plasma synthesis of mg-ni nanoparticles Aktekin, Burak; Öztürk, Tayfur; Department of Metallurgical and Materials Engineering (2013) There is a considerable interest in developing magnesium and magnesium alloys in the form of nanoparticles for hydrogen storage purposes. In the current study, induction thermal plasma was used to synthesize Mg-Ni nanoparticles. In this technique, precursors, which are normally powders, are fed to the thermal plasma where they are evaporated and nanoparticles are derived from condensation of this vapor in the quenching zone. RF induction plasma system used in the current work was operated at 25 kW and the r...
Catalytic hydrolysis of hydrazine borane for chemical hydrogen storage: Highly efficient and fast hydrogen generation system at room temperature Karahan, Senem; Zahmakiran, Mehmet; Özkar, Saim (2011-04-01) There has been rapidly growing interest for materials suitable to store hydrogen in solid state for transportation of hydrogen that requires materials with high volumetric and gravimetric storage capacity. B-N compounds such as ammonia-triborane, ammonia-borane and amine-borane adducts are well suited for this purpose due to their light weight, high gravimetric hydrogen storage capacity and inclination for bearing protic (N-H) and hydridic (B-H) hydrogens. In addition to them, more recent study [261 has sho...
Ruthenium nanoparticles supported on nanotubes/nanowires: highly active and long lived nanocatalysts in hydrolytic dehydrogenation of ammonia borane / Akbayrak, Serdar; Özkar, Saim; Department of Chemistry (2016) Ammonia borane (NH3BH3, AB) is one of the most promising solid hydrogen storage materials due to its high hydrogen storage capacity (19.6% wt.), non-toxicity and high stability under ambient conditions. Ammonia borane can release hydrogen upon hydrolysis in the presence of suitable catalysts even at room temperature. Although a large variety of catalysts have been tested in hydrogen generation from the hydrolysis of ammonia borane, the development of efficient, long-lived, reusable catalysts is still an imp...

Citation Formats

K. M. Aydınol, S. Tan, H. Akyıldız, A. Kınacı, and F. Şen, “Temel prensipler yöntemiyle magnezyum ve demir - titanyum hidrürlerinin modellenmesi, tasarımı ve üretimi,” 2008. Accessed: 00, 2020. [Online]. Available: https://app.trdizin.gov.tr/publication/project/detail/T0RJNU1EQT0.