0000000000222463
AUTHOR
Didier Leterq
showing 2 related works from this author
Gas–solid chromatographic separation of hydrogen isotopes: a comparison between two palladium bearing materials – alumina and kieselguhr
1998
The separation of hydrogen isotopes (H, D, T) is performed by displacement gas chromatography on palladium. A large isotopic effect is associated with the reversible adsorption of hydrogen by palladium. Two Pd support materials have been compared: alpha-alumina and kieselguhr. The study includes a physicochemical characterization and a set of functional tests. The Van Deemter model gives a fairly good analysis of the process but to get more information, thermoregulated separations are needed. For both supports, palladium is impregnated as small dispersed particles in the 0.1 to 0.3 μm range diameter. For the same palladium loading, alumina is more efficient than kieselguhr.
Relation between grain size and hydrogen diffusion coefficient in an industrial Pd–23% Ag alloy
1999
Abstract The diffusion mechanism of hydrogen in an industrial cold worked Pd–23% Ag alloy is investigated according to its grain size. The microstructural parameters are determined by X-ray diffraction analysis and the diffusion parameters are determined using the galvanostatic electrochemical permeation technique. Two diffusion mechanisms are displayed. For apparent grain size below 40 nm the hydrogen atoms diffuse in the grain boundaries. For grain size above 100 nm, an intergranular diffusion mechanism occurs. For intermediate grain size both mechanisms coexist. Furthermore, the diffusion in the grain boundaries is not faster than the diffusion in the bulk, as generally observed for pure…