Hydrogen Sorption and Rehydrogenation Properties of NaMgH3

The formation and hydrogen sorption properties of the NaMgH3 perovskite/type hydride have been examined. Samples were mechanically ball milled under argon for 2, 5 and 15 h; then characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) coupled with a mass spectrometer (MS). Lattice parameters and cell volume of the main NaMgH3 phase increase as a function of milling. Dehydrogenation proceeded in two-step reactions for the NaMgH3. The maximum amount of released hydrogen was achieved for the 2 h milled NaMgH3 hydride accounting for 5.8 wt.% of H-2 from 287 degrees C to 408 degrees C. Decomposed NaMgH3 samples were reversibly hydrogenated under 10 bar H-2 at ~200 degrees C.

Automated summary

The formation and hydrogen sorption properties of the NaMgH3 perovskite/type hydride were studied, and it was found that the lattice parameters and cell volume of the main NaMgH3 phase increased with milling time. The NaMgH3 hydride milled for 2 hours released the highest amount of hydrogen, which could be reversibly hydrogenated at about 200 degrees Celsius.