High purity silica from rice husk ash as catalyst in Mg-based hydrogen storage material
Zulkarnain Jalil, Ismail Ismail, Adi Rahwanto, Malahayati, Farid Mulana, Erfan Handoko

Universitas Syiah Kuala, Banda Aceh

Abstract

Magnesium hydrides (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%. In this study, nickel and silicon di-oxide catalysts were used to reduce the operational temperature of MgH2. In this work, we introduce the green catalyst of silicon di-oxide which was extracted from local rice husks ash. The purity of silica obtaine 98%. The composition of MgH2 + 5wt% Ni X wt% SiO2 (x=3,5,10,15) was prepared by mechanical alloying technique, by soft milling time. The characterization have been done by X-ray diffraction (XRD), scanning electron microscopy (SEM) for their phase composition and morphology, respectively. The desorption kinetics measured with gravimetric method. XRD results indicate a decrease in particle size with short milling time. MgH2 was obtained as the main phase followed by Ni and SiO2. SEM results showed that with the milling process, the particle is homogeneous. The nanopowders of Mg-based hydrides was succesfully produced by using mechanical alloying method.

Keywords: natural silica, rice husk ash, catalyst, hydrogen storage, milling

Topic: Material Science