MgH2-carbon composites for hydrogen storage

Abstract

Peculiarities of hydrogenation reactions of magnesium at temperatures of 410°C to 450°C and pressures of 15 to 55 MPa have been investigated. Interactions in MgH2-graphite system under quasihydrostatic conditions (3 GPa, 800°C, 1 h) have been explored. It has been shown that such a treatment did not lead to formation of new chemical compounds. The phase transformation of MgH2 to a metastable high-pressure modification has been found. As a result of mechanochemical activation, the MgH2-graphite and MgH2-CNF composites have been obtained. It has been pointed that the mechanical activation of mixtures of magnesium hydride with carbon affect strongly the kinetic parameters of hydrogen desorption but also led to decreasing the thermal stability of the hydride phase. © 2007 Springer.