Reaction pathways for hydrogen desorption from magnesium hydride/hydroxide composites: bulk and interface effects

文献情報

出版日 2009-11-16

DOI 10.1039/B912964B

インパクトファクター 3.676

著者

F. Leardini, J. R. Ares, J. Bodega, J. F. Fernández, I. J. Ferrer, C. Sánchez

原文を見る

要旨

This manuscript investigates the thermal desorption behaviour of MgH2/Mg(OH)2 composites by means of thermal desorption spectroscopy. Besides the H2O and H2 desorption events due to Mg(OH)2 dehydration and MgH2 decomposition reactions, respectively, two additional H2 desorption peaks arise at lower temperatures. These peaks are related to solid-state reactions between magnesium hydride and magnesium hydroxide through different channels. The low temperature H2 peak (∼150 °C) is related to reaction between a H atom diffusing from MgH2 and a surface OH group, whereas the intermediate temperature H2 peak (∼350 °C) is due to an interface reaction between the hydride and the hydroxide. The present work supports the theory that the onset of the H2 desorption coming from MgH2 decomposition is controlled by an incubation process, consisting in the formation of catalytically active vacancies at the MgO/Mg(OH)2 surface by dehydration. Possible ways to improve the H2 desorption kinetics from MgH2 are discussed in the light of the results obtained.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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