Metal-hydride transformation kinetics in Mg nanoparticles

TitleMetal-hydride transformation kinetics in Mg nanoparticles
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2009
AuthorsPasquini, L., Callini E., Piscopiello E., Montone A., Antisari M.V., and Bonetti E.
JournalApplied Physics Letters
KeywordsConstant rates, Fourier transforms, Growth (materials), Hydride formations, Hydride transformations, Hydrogen, Hydrogen cycling, Hydrogen sorptions, Inert gas condensations, Inert gases, Magnesium, Magnesium oxides, Magnesium printing plates, Nanoparticles, One-dimensional growths, Particle surfaces, Reverse transformations, Sorption, Three dimensional, Three-dimensional growths, Transmission electrons, Volumetric apparatus

The hydrogen sorption kinetics of magnesium nanoparticles prepared by inert gas condensation and coated by a magnesium oxide layer were investigated by a volumetric apparatus. The metal-hydride transformation was studied by transmission electron microscopy of the nanoparticles both in the as-prepared state and after hydrogen cycling. In small nanoparticles (≈35 nm) hydride formation proceeds by one-dimensional growth controlled by diffusion through the hydride, while the reverse transformation to metal involves interface-controlled three-dimensional growth of nuclei formed at constant rate. Large nanoparticles (≈450 nm) exhibit very low reactivity attributed to reduced probability of hydrogen dissociation/recombination and nucleation at the particle surface. © 2009 American Institute of Physics.


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