Hydrogen sorption kinetics of MgH sub(2 catalyzed with titanium compounds)

• Published in: International journal of hydrogen energy Vol. 35; no. 7; pp. 3046 - 3050
• Main Authors: Ma, Lai-Peng, Wang, Ping, Cheng, Hui-Ming
• Format: Journal Article
• Language: English
• Published: 01.04.2010
• Subjects: Anions; Catalysis; Catalysts; Hydrogen storage; Sorption; Titanium compounds; Titanium dioxide; X-ray photoelectron spectroscopy
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2009.07.014

Identification of effective catalyst is a subject of great interest in developing MgH sub(2 system as a potential hydrogen storage medium. In this work, the effects of typical titanium compounds (TiF) sub(3), TiCl sub(3, TiO) sub(2), TiN and TiH sub(2) on MgH) sub(2) were systematically investigated with regard to hydrogen sorption kinetics. Among them, adding TiF sub(3 leads to the most pronounced improvement on both absorption and desorption rates. Comparative studies indicate that the TiH) sub(2) and MgF sub(2 phases in situ introduced by TiF) sub(3) fail to explain the superior catalytic activity. However, a positive interaction between TiH sub(2 and MgF) sub(2) is observed. Detailed comparison between the effect of TiF sub(3 and TiCl) sub(3) additive suggests the catalytic role of F anion. XPS examination reveals that new bonding state(s) of F anion is formed in the MgH sub(2 + TiF) sub(3) system. On the basis of these results, we propose that the substantial participation of F anion in the catalytic function contributes to the superior activity of TiF sub(3.)