Hydro-quebec

UniversitÈ Laval

André Van Neste

Robert Schulz

Sabin Boily

Serge Kaliaguine

Jacques Huot

Guy Lalande

Guoxiang Liang

The invention concerns a method for preparing a nanocomposite based on magnesium and another element or compound known to absorb hydrogen and hardly miscible when ground with magnesium or its hydride, such as vanadium, titanium or niobium. The method is characterised in that it consists in submitting magnesium or a compound based on magnesium known to absorb hydrogen to hydrogenation to obtain the corresponding hydride in powder form. Said resulting powder hydride is then mixed with the other element or compound or a hydride of said other element or compound and the resulting mixture is subjected to intense mechanical grinding until the corresponding nanocomposite is obtained in the form of a hydride. Finally, if necessary, the resulting nanocomposite is subjected to hydrogen desorption. The invention also concerns the resulting nanocomposite based on Mg, which has the advantage of being inexpensive and highly efficient for storing hydrogen owing to its microstructure (that is owing to the nature of its interfaces and the spatial distribution of its constituents) which is extremely fine and provides an excellent synergistic effect between Mg and the other element or compound.

Nanocomposites with activated interfaces prepared by mechanical grinding of magnesium hydrides and use for storing hydrogen

Perovskite-type structure compounds having the general empirical formula ABO.sub.3 are prepared by a process comprising subjecting a mixture of starting powders formulated to contain the components represented by A and B in the formula to a high energy milling sufficient to induce chemical reaction of the components and thereby synthesize a mechanically-alloyed powder comprising the perovskite in the form of nanostructural particles. The process according to the present invention is simple, efficient, not expensive and does not require any heating step for producing a perovskite that may easily show a very high specific surface area. Another advantage is that the perovskite obtained according to the present invention also has a high density of lattice defects thereby showing a higher catalytic activity, a characteristic which is highly desirable in their eventual application as catalysts and electronic conductors.

Process for synthesizing perovskites using high energy milling

Growing community of inventors

Sainte-Foy, Canada

André Van Neste