Effect of LaCoO3 Synthesized via Solid-State Method on the Hydrogen Storage Properties of MgH2

One of the ideal energy carriers for the future is hydrogen. It has a high energy density and is a source of clean energy. A crucial step in the development of the hydrogen economy is the safety and affordable storage of a large amount of hydrogen. Thus, owing to its large storage capacity, good reversibility, and low cost, Magnesium hydride (MgH2) was taken into consideration. Unfortunately, MgH2 has a high desorption temperature and slow ab/desorption kinetics. Using the ball milling technique, adding cobalt lanthanum oxide (LaCoO3) to MgH2 improves its hydrogen storage performance. The results show that adding 10 wt.% LaCoO3 relatively lowers the starting hydrogen release, compared with pure MgH2 and milled MgH2. On the other hand, faster ab/desorption after the introduction of 10 wt.% LaCoO3 could be observed when compared with milled MgH2 under the same circumstances. Besides this, the apparent activation energy for MgH2-10 wt.% LaCoO3 was greatly reduced when compared with that of milled MgH2. From the X-ray diffraction analysis, it could be shown that in-situ forms of MgO, CoO, and La2O3, produced from the reactions between MgH2 and LaCoO3, play a vital role in enhancing the properties of hydrogen storage of MgH2.

Automated summary

Hydrogen is an ideal energy carrier for the future due to its high energy density and cleanliness. The safe and affordable storage of hydrogen is a crucial step in the development of the hydrogen economy. Magnesium hydride (MgH2) is considered for its large storage capacity, good reversibility, and low cost. However, it has limitations such as high desorption temperature and slow kinetics. Adding cobalt lanthanum oxide (LaCoO3) to MgH2 through ball milling improves its hydrogen storage performance.