The intermetallic compound is made by rotating microparticles of magnesium and aluminum at high speed under vacuum conditions at room temperature. This process of mechanical alloying yields a compound that is all in the so-called gamma phase. By optimizing the ratio of magnesium to aluminum and adding 1 per cent niobium oxide as a catalyst, the researchers obtained a material able to absorb 4.3 per cent its weight in hydrogen.

Other criteria set by the automakers are that the hydrogen absorption compound work at temperatures of 150-200 degrees Celsius (C) and absorb and release the hydrogen in 10 minutes.

The new compound operates at 300 C and takes around an hour to absorb and release hydrogen, but the researchers believe that they can clear both hurdles by using a different catalyst.

Compounds based on palladium can absorb more than 5 per cent hydrogen, but this metal is very expensive. Other hydrogen absorption compounds based on lanthanum and titanium have been developed, but have low absorption rates of 1-2 per cent.

(Nikkei)