Method of rapidly carrying out hydrogenation of hydrogen storage material

Abstract

Disclosed is a method for rapidly carrying out a hydrogenation of a material capable of absorbing hydrogen. It was discovered that when a powder of a material capable of absorbing hydrogen is ground under a hydrogen pressure, not at room temperature but at a higher temperature (about 300 DEG C. in the case of magnesium) and in the presence of a hydrogenation activator such as graphite and optionally a catalyst, it is possible to transform completely the powder of this material into a hydride. Such a transformation is achieved in a period of time less than 1 hour whereas the known methods call for periods of time as much as 10 times longer. This is an unexpected result which gives rise to a considerable reduction in the cost of manufacture of an hydride, particularly MgH2.

Description

field of invention

[0001] The present invention relates to a method for the rapid hydrogenation of hydrogen storage materials. Background technique

[0002] The hydrogenation, more specifically the first hydrogenation, of materials known to be able to absorb hydrogen can be very difficult, since there are often native oxides present on the surface of the material which hinder the penetration of hydrogen. Therefore, one has to break this barrier to carry out the first hydrogenation of the material. Thereafter, the second hydrogenation and subsequent hydrogenations are more easily carried out.

[0003] The first hydrogenation, which destroys the oxide coating the surface of the material, is called "activation". This activation is typically achieved by exposing the hydrogen storage material to high temperatures (typically several hundred degrees Celsius) and high hydrogen pressure (typically 15-50 bar). The lower the temperature and pressure required for the hydrogenation, t...