X-ray absorption spectroscopy study for the effect of TiCl on the hydrogen storage property of Mg(BH)

Matsumura, Daiju   ; Oyama, Takahiro*; Okajima, Yuka; Nishihata, Yasuo; Li, H.-W.*; Ikeda, Kazuki*; Orimo, Shinichi*

Mg(BH) shows 14.9% mass density of hydrogen and has attracted much attention in many years. Recently, it was reported that the hydrogen desorption temperature decreases from 530 K to 360 K by TiCl doping. In this study, we applied the X-ray absorption fine structure spectra to the static and dynamic observations in order to understand the local structure around doped Ti atoms. It has been revealed that the hydrogen desorption around 420 K is induced by the resolution of Ti(BH) generated from the reaction of TiCl and Mg(BH). Another hydrogen desorption reaction over 470 K was considered to be induced by the catalytic reaction of TiB.