Use of carbon nanostructures for hydrogen storage for environmentally safe automotive applications

Carbon nanostructures are considered materials with a high potential for hydrogen storage. CCVD technique was used to grown nanotubes with diameters ranging from 50 to 100 nm on a Ni:Cu catalyst and nanofibers with diameters ranging from 10 to 100 nm on a Pd/La/sub 2/O/sub 3/ catalyst. The hydrogen uptake experiments performed volumetrically in a Sievert-type installation, showed the quantity of desorbed hydrogen (for pressure intervals ranging from 1 to 100 bars) by the nanotubes was less than 1 % by weight. The hydrogen sorption capacities of the carbon nanofibers show saturation value of about 1.5 wt. % and to be in a good correlation with the Pd/C ratio, revealing a catalytic effect of Pd that supplies atomic H.