MgH2-SiC based hydrogen storage material prepared by reactive mechanical alloying method

Abstract

Hydrogen storage in metal hydrides, compared to conventional methods, is regarded as one of the best solutions due to the higher volumetric storage capacity and safety. Magnesium and magnesium-based alloys are promising candidates for hydrogen storage. The hydrogen storage capacity of magnesium in the form of MgH2 amounts to 7.6 wt%. Unfortunately, Mg has a high thermodynamic stability and therefore, relatively slow desorption kinetics, which are the major drawbacks for the application as a hydrogen storage material. Various techniques are developed to improve the sorption characteristics by accelerating the aforesaid processes. In this work we success to synthesis and investigate the catalytic effect of SiC and Ni (in nanostructure scale) on MgH2 using reactive mechanical alloying method in 10 bar H2. At first step, using SiC catalyst the sorption properties can be improved. The most promising step by using double catalysts of SiC and Ni (MgH2-5wt%SiC-5wt%Ni) which absorp 5.7 wt% hydrogen and at the same time decrease the desorption temperature to 250°C. Compared to T onset of pure MgH2 -which desorp at 380° C. To the best of our knowledge, this is the best result so far for MgH2-SiC system.