Hydrogen storage properties of nano-composites of Mg and Zr-Ni-Cr alloys

Mg and Zr-Ni-Cr alloy nano-composite hydrogen storage materials have been p repared by high energy mechanical milling (MM) of Mg powders with either cr ystalline ZrNiCr and ZrNi1.6Cr0.4 powders or mechanically milled amorphous ZrNiCr and ZrNi1.6Cr0.4 powders. Nano-composites of amorphous Zr-Ni-Cr allo y and Mg have better desorption kinetics compared to crystalline Zr-Ni-Cr a lloy and Mg nano-composites. Amorphous ZrNi1.6Cr0.4 and Mg nano-composites desorb larger amount of H-2 much faster than amorphous ZrNiCr and Mg nano-c omposites, The nano-composite of 35 wt.% amorphous ZtNi(1.6)Cr(0.4) and Mg releases 4.3 wt.% H-2 at 300 degrees C in 30 min. X-ny diffraction revealed that there are no reactions between Mg and Zr-Ni-Cr alloys in the milling, activation, and subsequent cycling processes, proving that amorphous ZrNi1 .6Cr0.4 is an effective hydrogen absorption and desorption catalyst. (C) 20 00 Elsevier Science B.V. All rights reserved.