Synthesis and characterization of MgZr alloy for hydrogen storage

Abstract

Fossil fuels depleting day to day due to which the shift to renewable energy source is essential. The major concern for carbon emissions which is about 360% where ash and sulphur has lowest value with 40% and 1.5% in 1000 MW power plant. The idea of renewable energy usage discovered in the early 1800′s not to completely rely on conventional energy production. Though, the source of energy is intermittent they offer zero emissions during power production. Hence, storage is essential. The storage devices plays a prominent role in power production. Hydrogen is used as an input to the fuel cells as the by-product released is water in form of vapour. Contemporarily, the only materials are capable of storing and releasing hydrogen in ambient conditions are LaNi5 and TiFe, hence they are used in large scale productions. However, these materials has less gravimetric storage capacity of 1.2 wt% and 1.9 wt% respectively. The best material with benefits such as low cost, availability and storage capacity is Mg with 7.6 wt% of hydrogen. Despite, its high gravimetric storage capacity a few factors that lack in choosing for mobile applications such as slow kinetics and thermodynamic stability. Due to its low cost production, high energy density and light weight material still it is considered a subject of interest. The above mentioned drawbacks can be overcome by forming into Nano particles and adding catalyst post alloy formation with transition metals via non-equilibrium techniques such as ball-milling and the process of milling, process variables involved as discussed in [4]. This paper focuses on Mg alloyed with Zr with different compositions viz., 20 at.% and 35 at.% of Zr for which material characterisation has been examined. The computational study has been carried out and observed that at around 14 at.% of Zr when alloyed with Mg bring out better reversible storage capacities.