The use of silicon oxide extracted from rice husk ash as catalyst in magnesium hydrides (MgH2) prepared by mechanical alloying method

Abstract

MgH2 is one of the most promising material for hydrogen storage application, since its reversible and able to store hydrogen in large amounts of 7.6wt%. However, to be applied as a hydrogen absorber material, this material still has a deficiency, its kinetic reaction is still very slow and its operational temperature is still high. In this study, nickel and silicon oxide catalysts were used to reduce the operational temperature of MgH2. The silicon oxide used in this study was extracted from rice husks ash. The composition of MgH2 +SiO2 5wt% + Ni 10wt% was prepared by mechanical alloying technique, by varying milling time 0, 1, 5, 10 and 15 hours. XRD results indicate a decrease in particle size with longer milling time. MgH2 was obtained as the main phase followed by Ni and SiO2. SEM results showed that the longer milling time, the more particle size is homogeneous. Furthermore, thermal investigation using DSC showed that the desorption temperature obtained was in the range of values of 334.62 °C to 347.85 °C. The addition of 5 wt% SiO2 and 10 wt% Ni have improved sorption temperature and kinetic of MgH2.