Study on reaction mechanism of dehydrogenation of magnesium hydride by in situ transmission electron microscopy

In situ observation on dehydrogenation of MgH 2 was performed by using transmission electron microscope (TEM). The dehydrogenation of MgH 2 with 1 mol % Nb 2 O 5 and formation of nanosized Mg particles were observed at 150 ° C . Nb 2 O 5 was not confirmed in diffraction patterns and TEM images probably due to wide dispersion. On MgH 2 with 10 mol % Nb 2 O 5 , the high resolution TEM could recognize the dehydrogenation at the interface between MgH 2 and Nb 2 O 5 , proceeding with increasing temperature. This suggests that hydrogen atoms could diffuse from MgH 2 phase to the interface between Mg and Nb 2 O 5 , resulting in formation of hydrogen molecules at the interface. At the request of the authors, this article is being retracted effective 27 June 2017.