Microstructure and hydrogen storage properties of Ti-doped NaH/Al composites prepared by ball-milling

In this paper, the, microstructure and hydrogen storage properties of the ( NaH/Al) + x (molar fraction, %) Ti ( x = 0, 4, 6, 10) composites were investigated. It was found that the reversible hydrogen storage properties can be improved by mechanically ball-milling the( NaH/Al) mixture together with Ti powder. H2 is a better ball-milling atmosphere than Ar, because a part of NaH is consumed during the ball-milling under an Ar atmosphere. As the Ti content increases, the hydrogen storage properties are enhanced gradually. In case of x = 10, the reversible hydrogen absorption/desorption capacities of the composites milled for 6 h under the H2 atmosphere reach 4.01% and 3.93% ( mass fraction), respectively. The catalytic mechanism of the Tidoped NaH/Al composites system is discussed briefly.