Hydrogen sorption improvement of nanocrystalline MgH2 by Nb2O5 nanoparticles

The influence of Nb2O5 nanoparticles (15 nm) as an additive for mechanical milling on the hydrogen sorption kinetics of MgH2 was investigated. By using nanometric Nb2O5, a significant reduction of milling time (200 times shorter) with a decrease of desorption temperature by 60 °C were observed in comparison to its micrometric form. X-ray diffraction and hydrogen sorption measurements led to the proposal of two possible mechanisms for the hydrogen sorption based on an intimate contact between MgH2 and Nb2O5.