Kinetics of tantalum hydriding: the effect of palladization

Hydrogen production and storage—Investigation of Hf-based intermetallics

“…4 and 5. It could be concluded that, as expected for simple hydride forming alloys [20], the partial decomposition of the alloy occurs during cycling. However, the lattice parameters of the remaining Hf 2 Ni were maintained.…”

“…After grinding, hydriding and dehydriding were carried out in typical volumetric equipment [20]. A quartz tube containing a weighed quantity of the sample powder (about 100 mg) was inserted into a thermostated tube furnace.…”

“…The SEM micrographs of Hf 2 Ni powder pointed out that after 20 absorption/desorption cycles the average particle diameter (7 m) was apparently not affected. However, numerous cracks appear along the particles, which are particularly visible under the amplification 2000, as a known consequence of the repetition hydriding/dehydriding cycles [20]. These considerations are important in the possible usage of Hf-based intermetallics as hydrogen storage materials.…”

“…Metal hydrides are widely investigated [7,8] in order to evaluate the scope of their application in hydrogen storage devices. Hf 2 Fe, Hf 2 Co and Hf 2 Ni have been investigated as systems interesting for hydrogen storage, since they are able to form hydrides in hydrogen-metal atom ratios H/M ≥ 1 at rather high temperatures and high pressures (>1 kPa) (T ≈ 3000 • C) [7].…”

Surface-modified advanced hydrogen storage alloys for hydrogen separation and purification

“…PGM coatings, being extremely active towards dissociative H 2 chemisorption enable hydrogen to rapidly absorb in the bulk material, while still maintaining the hydrogenation activity even after extensive exposure to the impurities inhibiting hydrogen sorption. Various methods were used for the introduction of PGM into the substrate, including electrochemical [11] and electroless [11][12][13][14] plating techniques, PVD [11,15], or mechanical treatment [16][17][18][19][20][21]. The obtained PGM-containing composites were characterised by superior, as compared to the parent MH material, hydrogenation/dehydrogenation performances which were not significantly deteriorated after long-term exposure to aggressive environments.…”