Magnesium hydride(MgH_(2))is the most feasible and effective solid-state hydrogen storage material,which has excellent reversibility but initiates decomposing at high temperatures and has slow kinetics performance.Her...Magnesium hydride(MgH_(2))is the most feasible and effective solid-state hydrogen storage material,which has excellent reversibility but initiates decomposing at high temperatures and has slow kinetics performance.Here,zinc titanate(Zn_(2)TiO_(4))synthesised by the solid-state method was used as an additive to lower the initial temperature for dehydrogenation and enhance the re/dehydrogenation behaviour of MgH_(2).With the presence of Zn_(2)TiO_(4),the starting temperature for the dehydrogenation of MgH_(2)was remarkably lowered to around 290℃–305℃.In addition,within 300 s,the MgH_(2)–Zn_(2)TiO_(4)sample absorbed 5.0 wt.%of H_(2)and 2.2–3.6 wt.%H_(2)was liberated from the composite sample in 30 min,which is faster by 22–36 times than as-milled MgH_(2).The activation energy of the MgH_(2)for the dehydrogenation process was also downshifted to 105.5 k J/mol with the addition of Zn_(2)TiO_(4)indicating a decrease of 22%than as-milled MgH_(2).The superior behaviour of MgH_(2)was due to the formation of Mg Zn_(2),MgO and MgTiO_(3),which are responsible for ameliorating the re/dehydrogenation behaviour of MgH_(2).These findings provide a new understanding of the hydrogen storage behaviour of the catalysed-MgH_(2)system.展开更多
基金Universiti Malaysia Terengganu(UMT)for the funding provided by Golden Goose Research Grant(GGRG)VOT 55190。
文摘Magnesium hydride(MgH_(2))is the most feasible and effective solid-state hydrogen storage material,which has excellent reversibility but initiates decomposing at high temperatures and has slow kinetics performance.Here,zinc titanate(Zn_(2)TiO_(4))synthesised by the solid-state method was used as an additive to lower the initial temperature for dehydrogenation and enhance the re/dehydrogenation behaviour of MgH_(2).With the presence of Zn_(2)TiO_(4),the starting temperature for the dehydrogenation of MgH_(2)was remarkably lowered to around 290℃–305℃.In addition,within 300 s,the MgH_(2)–Zn_(2)TiO_(4)sample absorbed 5.0 wt.%of H_(2)and 2.2–3.6 wt.%H_(2)was liberated from the composite sample in 30 min,which is faster by 22–36 times than as-milled MgH_(2).The activation energy of the MgH_(2)for the dehydrogenation process was also downshifted to 105.5 k J/mol with the addition of Zn_(2)TiO_(4)indicating a decrease of 22%than as-milled MgH_(2).The superior behaviour of MgH_(2)was due to the formation of Mg Zn_(2),MgO and MgTiO_(3),which are responsible for ameliorating the re/dehydrogenation behaviour of MgH_(2).These findings provide a new understanding of the hydrogen storage behaviour of the catalysed-MgH_(2)system.
