Kinetic limitations in the Mg-Si-H system

Paskevicius, M. and Sheppard, D. A. and Chaudhary, A.-L. and Webb, C. J. and Gray, E. Mac A. and Tian, H. Y. and Peterson, V. K. and Buckley, C. E. 2011. Kinetic limitations in the Mg-Si-H system. International Journal of Hydrogen Energy. 36 (17): pp. 10779-10786.

Source Title

International Journal of Hydrogen Energy

DOI

10.1016/j.ijhydene.2011.05.132

ISSN

0360-3199

School

Department of Imaging and Applied Physics

URI

http://hdl.handle.net/20.500.11937/40272

Collection

Curtin Research Publications

Abstract

Magnesium silicide (Mg2Si) has attracted interest as a hydrogen storage material due to favorable thermodynamics (ΔHdesorption = 36 kJ/mol H2) for room temperature operation. To date, direct hydriding of Mg2Si under hydrogen gas to form MgH2 and Si has only been attempted at low pressure and has been hindered by poor kinetics of absorption. In this paper we study the dehydrogenation reaction with in-situ neutron powder diffraction and present results of our attempts to hydrogenate Mg2Si under both hydrogen and deuterium gas up to temperatures of 350 °C and pressures of 1850 bar. Even under these extreme absorption conditions Mg2Si does not absorb any measureable quantity of hydrogen or deuterium.