Characteristics of Hydrogen Storage by Sn/MgH₂ Nanocomposite Obtained by Mechanical Milling of MgH₂ with Sn

Abstract

The hydrogen desorption of Sn/MgH2 nanocomposite which is formed by ball milling of MgH2 and tin compounds (Sn, Sn(C4H9)4 or SnCl2), has been studied. The hydrogen desorption properties (desorption temperature and enthalpy of dehydriding) were significantly improved as a result of a Sn/MgH2 nanocomposite formation. TDS (thermal desorption spectrometry), TG (thermogravimetry) and DSC (differential scanning calorimeter) measurements exhibited the existence of at least two types of hydrogen species in the Sn/MgH2 nanocomposite resulting from ball milling of MgH2 with Sn; the one was hydrogen in the newly formed Sn/MgH2 nanocomposite and the other hydrogen derived from MgH2 remaining in Sn/MgH2.

Hydrogen storage properties of nanocrystalline MgH2 and MgH2/Sn nanocomposite synthesized by ball milling

“…b The sample was evacuated for 1 h. c The sample was not rehydrogenated; as evacuated. nanocrystalline MgH 2 are significantly improved [13,14]. The onset of hydrogen desorption from MgH 2 /Sn(17 at%) falls to about 440 K, compared with 500 K for MgH 2 milled with cyclohexane.…”

“…The sample preparation of nanocrystalline MgH2 [10] and MgH2/Sn nanocomposite [13,14] was carried out using a planetary-type ball mill (High G: BX 254; Kurimoto Ltd.), being capable of operating at a 863-rpm maximum speed. In a typical preparation of nanocrystalline MgH2, magnesium hydride (3.0 g) and cyclohexane (2.0 cm 3 ) were placed in a grinding bowl (coated with zirconia; cylindrical shape with volume of 160 cm 3 ) flushed thoroughly with dry nitrogen.…”

“…Moreover, MgH 2 /Sn nanocomposites obtained when the nanocrystalline MgH 2 is ball-milled with Sn have been studied [13,14]. The nanocomposite formation of MgH 2 /Sn further improved the hydrogen sorption characteristics of magnesium hydride; the desorption temperature of hydrogen from MgH 2 /Sn fell below 490 K, compared to 530 K from MgH 2 .…”