YOSHIDA Lab. Ryusuke Tominaga

1. Mg-H dissociation of magnesium hydride MgH2 catalyzed by 3d transition metalsThin Solid Films Muneyuki Tsuda, Wilson Agerico Diño, Hideaki Kasai, Hiroshi Nakanishi and Hiroshi Aikawavol 509 157-159 2006 YOSHIDA Lab. Ryusuke Tominaga

2. Contents Introduction • The purpose of the research • The method to solve the problem • Hydrogen Absorbing Materials The design of Hydrogen Absorbing Materials summary

3. The purpose of research • The purpose of the research is through creating high-quality hydrogen absorbing materials , to encourage the prevalence of fuel-cell electric vehicle , and thereby to contribute to the solving of the energy and environment concern .

4. fuel-cell electric vehicle 「ＰＵＹＯ」 ①No emissions of carbon dioxide （->) environment concern ②The efficiency of fuel-cell electric vehicle is about 2 times more efficient than that of normal vehicle (->energy concern) 出典：http://www.nikkei.co.jp/news/main/im20071009AS1D0904609102007.html

5. The hierarchy of industrial structure Computational Nano Materials Design The change of industrial structure System device material

6. The hierarchy of industrial ctructure Computational Nano Materials Design The change of industrial structure fuel-cell electric vehicle Fuel cell Hydrogen Absorbing Materials

7. What are the Hydrogen Absorbing Materials ? The Hydrogen Absorbing Materials are the materials that can absorb and emit hydrogen. The discover ：the Philips Eindhoven institution （Netherlands)

8. The condition that must be satisfied to be a practical Hydrogen Absorbing system ①Can the system contain enough fuel for about 480km drive ranges at one time refilling ? -> over 6 (wt%) ②Can it release enough hydrogen to provide the power and acceleration that driver expects at about 350(K) ?

9. The examples of Hydrogen Absorbing Materials • Chemical hydrides • Compressed hydrogen • Liquid hydrogen • Hydrogen adsorbents • Complex hydrides

10. http://www.eerj.co.jp/jp/Reference/Reference20070803/images/ExtractScientificAmericanJ.pdfhttp://www.eerj.co.jp/jp/Reference/Reference20070803/images/ExtractScientificAmericanJ.pdf

11. Specific material • MgH2 Mg-H dissociation of magnesium hydride MgH2 catalyzed by 3d transition metals Thin Solid Films Muneyuki Tsuda, Wilson Agerico Diño, Hideaki Kasai, Hiroshi Nakanishi and Hiroshi Aikawa vol 509 157-159 2006

12. MgH2 • Hydrogen capacity :7.66 wt% -> ( the condition ①:over 6 (wt%) ) • H2 desorption temperature :700K -> ( the conditon② : About 350(K) )

13. The used model Fig. 1. MgH2 + M (M: Sc to Zn) configurations with C2v symmetry. We put the M atom on top of the Mg of the MgH2.

14. The calculation condition • Gaussian03 is used. • M: Sc - Zn • DFT • B3pW91 6-31G(d,p) • LANL2DZ

15. Calculated potential energy curves Fig. 2. Calculated potential energy curves for the MgH2 + M (M: Sc to Zn) systems in Fig. 1 as a function of the Mg–H distance. In these calculations, the Mg–M distance is allowed to relax. The potential energies are defined as the energies required to increase the Mg–H distance from their equilibrium positions.

16. Calculated H2 desorption temperatures (Redhead’s equation) Fig. 3. Calculated H2 desorption temperatures as a function of the activation barrier for the Mg–H bond cleavage.

17. summary • H2 desorption temperature -> 700 K (no M) -> 500 K (with Sc or Ni) • To be a practical Hydrogen Absorbing Materials , the H2 desorption temperature should be about 350 (K) . • The further research is needed in order to weaken the Mg-H bond of MgH2.