Kinetic and thermodynamic aspects of Mg and Mg-Ti hydride nanomaterials

Reliable and affordable energy storage represents a bottleneck in a scenario where renewable energy sources become prominent on the energy market. With its high potential energy density and the natural abundance of the element, hydrogen gas is an attractive energy storage medium. But its gaseous nature, its high explosive potential and...

Destabilization of magnesium hydride through interface engineering

The aim of this thesis is to study the thermodynamics of hydrogenation of nanoconfined magnesium within a thin film multilayer model system. Magnesium hydride is a potential material for hydrogen storage, which is a key component in a renewable energy system based on hydrogen. In bulk form, magnesium hydride is very stable, which means that...

Fractal disperse hydrogen sorption kinetics in spark discharge generated Mg/NbOx and Mg/Pd nanocomposites

Isothermal hydrogen desorption of spark discharge generated Mg/NbOx and Mg/Pd metal hydride nanocomposites is consistently described by a kinetic model based on multiple reaction rates, in contrast to the Johnson-Mehl-Avrami-Kolmogorov [M. Avrami, J. Phys. Chem. 9, 177 (1941); W. A. Johnson and R. F. Mehl, Trans. Am. Inst. Min., Metal. Eng. 135,...

Divacancies and the hydrogenation of Mg-Ti films with short range chemical order

We obtained evidence for the partial chemical segregation of as-deposited and hydrogenated Mg1?yTiy films (0 ? y ? 0.30) into nanoscale Ti and Mg domains using positron Doppler-broadening. We exclusively monitor the hydrogenation of Mg domains, owing to the large difference in positron affinity for Mg and Ti. The electron momentum distribution...

Thermal stability of gas phase magnesium nanoparticles

In this work we present a unique transmission electron microscopy study of the thermal stability of gas phase synthesized Mg nanoparticles, which have attracted strong interest as high capacity hydrogen storage materials. Indeed, Mg nanoparticles with a MgO shell ( ? 3?nm thick) annealed at 300?°C show evaporation, void formation, and void...

Quasifree Mg–H thin films

The thermodynamics of hydrogen absorption in Pd-capped Mg films are strongly dependent on the magnesium thickness. In the present work, we suppress such dependency by inserting a thin Ti layer between Mg and Pd. By means of optical measurements, we show that the surface energy contribution to the destabilization of MgH2 is negligible. The...

Positron depth profiling of the structural and electronic structure transformations of hydrogenated Mg-based thin films

We report positron depth-profiling studies on the hydrogen sorption behavior and phase evolution of Mg-based thin films. We show that the main changes in the depth profiles resulting from the hydrogenation to the respective metal hydrides are related to a clear broadening in the observed electron momentum densities in both Mg and Mg2Ni films....

Towards a hydrogen-driven society? Calculations and neutron scattering on potential hydrogen storage materials

For sustainable development, the resources of the earth need to be maintained and carbon dioxide emission should be avoided. In particular, we need to find an alternative for the use of fossil fuels in vehicles. Since long, hydrogen has been recognised as the fuel of the future because it exhausts only water when used in fuel cells and hardly...

Design of a magnesium removal process for an electrolytic zinc plant

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