Enhancement of hydrogen storage in MgNi by Pd-coating

MgNi alloys prepared by mechanical alloying were coated with Pd nanoparticles via a polyol process. Such a process allows the deposition of fine particles of metal catalysts on the MgNi alloy surface. This surface modification leads to a strong improvement of the H storage performances of the alloy. The hydrogen release at 150 degreesC increases from 0.6 wt.% for uncoated MgNi alloy to 1.5 wt.% for a 5 wt.% Pd-coated MgNi alloy. The strong enhancement of the desorption capacity probably results from the catalytic effect of Pd, which may act as a hydrogen pump, thus favoring hydrogen migration from the bulk to the surface of the alloy. (C) 2003 Elsevier B.V. All rights reserved.