Effect of CeH2.73-CeO2 Composites on the Desorption Properties of Mg2NiH4

Kaiyao Wu; Daqian Cai; Kaimei Shao; Tuguang Xue; Peng Zhang; Wei Li; Huai-Jun Lin

doi:10.3389/fchem.2020.00293

Effect of CeH_2.73-CeO₂ Composites on the Desorption Properties of Mg₂NiH₄

Front Chem. 2020 Apr 15:8:293. doi: 10.3389/fchem.2020.00293. eCollection 2020.

Authors

Kaiyao Wu¹, Daqian Cai¹, Kaimei Shao¹, Tuguang Xue¹, Peng Zhang¹, Wei Li¹, Huai-Jun Lin¹

Affiliation

¹ Institute of Advanced Wear and Corrosion Resistant and Functional Materials, Jinan University, Guangzhou, China.

Abstract

A series of CeH_2.73/CeO₂ composites with different ratios of hydride and oxide phases are prepared from the pure cerium hydride via oxidation treatments in the air at room temperature, and they are subsequently doped into Mg₂NiH₄ by ball milling. The desorption properties of the as-prepared Mg₂NiH₄+CeH_2.73/CeO₂ composites are studied by thermogravimetry and differential scanning calorimetery. Microstructures are studied by scanning electron microscopy and transmission electron microscopy, and the phase transitions during dehydrogenation are analyzed through in situ X-ray diffraction. Results show that the initial dehydrogenation temperature and activation energy of Mg₂NiH₄ are maximally reduced by doping the CeH_2.73/CeO₂ composite with the same molar ratio of cerium hydride and oxide. In this case, the CeH_2.73/CeO₂ composite has the largest density of interface among them, and the hydrogen release effect at the interface between cerium hydride and oxide plays an efficient catalytic role in enhancing the hydrogen desorption properties of Mg₂NiH₄.

Keywords: CeH2.73/CeO2; Hydrogen storage materials; Mg2NiH4; catalysts; dehydrogenation.