Carbon-modified MgH2 : experimental and ab-initio investigations

Toufic Tayeh (1, 2) , Abdel Salam Awad (1, 2) , Michel Nakhl (1) , Jean-Louis Bobet (2) , Mirvat Zakhour (1) , Samir F. Matar (2)

1 LCPM - Laboratoire de Chimie Physique des Matériaux
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

The results of experimental and theoretical investigations of carbon-modified MgH2 for improving its sorption performances in hydrogen storage devices are reported. Large changes on its absorption/desorption capacities have been found. The following aspects are considered: size effects where finer particles obtained by energetic ball milling enable easier penetration, catalytic effects of carbon at the surface, and entrance of small quantities of C interstitially into the MgH2 structure. The energies and charge densities as studied by DFT suggest the activation of MgH2 through a decrease of the cohesive energy of the pristine hydride and a reduced ionic charge on hydrogen.

Mots clés: Magnesium Hydride; Ball Milling; Carbon Doping; DFT; ELF

Domaines: Matériaux; Chimie théorique et/ou physique

Toufic Tayeh, Abdel Salam Awad, Michel Nakhl, Jean-Louis Bobet, Mirvat Zakhour, et al.. Carbon-modified MgH2 : experimental and ab-initio investigations. Zeitschrift fur Naturforschung B, 2014, 69 (7), pp.804-810. ⟨10.5560/ZNB.2014-4072⟩. ⟨hal-01059221⟩