In-situ TEM observation for reaction mechanism in MgH2 hydrogen storage material

Abstract

In-situ observation of the catalytic action of MgH2-1 mol%Nb2O5 and MgH2-10 mol%Nb2O 5 was carried out by using transmission electron microscopy (TEM). In case of MgH2-1 mol%Nb2O5, TEM analysis indicated that MgH2 started to decompose at 150°C and nano-size particle of Mg formed. However, Nb2O5 was not observed in the diffraction pattern and images. In case of MgH2-10 mol%Nb 2O5, high resolution images, FFT and IFFT, revealed that the decomposition of MgH2 started with the contact region in Nb 2O5 and Mg formed. The result suggested that the reaction of dehydration could proceed due to hydrogen diffusion to the Mg-Nb 2O5 interface. © 2010 The Japan Institute of Metals.