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Correlation between kinetics and chemical bonding state of catalyst surface in catalyzed magnesium hydride
| Title: | Correlation between kinetics and chemical bonding state of catalyst surface in catalyzed magnesium hydride |
| Authors: | Ma, Tao Browse this author | | Isobe, Shigehito Browse this author →KAKEN DB | | Morita, Eri Browse this author | | Wang, Yongming Browse this author | | Hashimoto, Naoyuki Browse this author | | Ohnuki, Somei Browse this author | | Kimura, Toru Browse this author | | Ichikawa, Takayuki Browse this author | | Kojima, Yoshitsugu Browse this author |
| Keywords: | Hydrogen storage materials | | MgH2 | | Oxide catalyst | | XPS | | TEM |
| Issue Date: | Sep-2011 |
| Publisher: | Elsevier |
| Journal Title: | International Journal of Hydrogen Energy |
| Volume: | 36 |
| Issue: | 19 |
| Start Page: | 12319 |
| End Page: | 12323 |
| Publisher DOI: | 10.1016/j.ijhydene.2011.07.011 |
| Abstract: | We reported on the hydrogen desorption properties, microstructure, kinetics, and chemical bonding state of catalyst surface for composites of MgH2 and 1 mol% Nb2O5 ball-milled for 0.02 h, 0.2 h, 2 h, 20 h under 1 MPa H2 atmosphere, as well as hand-mixed (HM) one. Hydrogen desorption properties were significantly improved by ball-milling with Nb2O5. Then, we estimated by Kissinger Method the activation energy (Ea) of hydrogen desorption reaction that decreased with the increase of ball-milling time. Especially, Ea of the sample ball-milled for 0.2 h was drastically decreased, compared with that of the sample ball-milled for 0.02 h. TEM observations revealed that the distribution of Nb2O5 in MgH2 was gradually improved during ball-milling. On the other hand, we confirmed by XPS that in the sample ball-milled for 0.2 h, Nb_[2]O_[5-x] phase(s) existed at least on the surface. It can be suggested that these deoxidized Nb_[2]O_[5-x] phases eventually decrease Ea as substantial catalyst rather than Nb2O5 itself. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/47469 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 礒部 繁人
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