Nanoparticle nitrogen-doped lanthanum titanate as a MgH2 catalyst to provide enhanced hydrogen storage properties

• Published in: Journal of alloys and compounds 2024-12, Vol.1009, p.176975, Article 176975
• Main Authors: He, Qingjie, Sun, Weiqi, Li, Hongfei, Wang, Yazhou, Yin, Chengwang, Xiang, Cuili, Zou, Yongjin, Xu, Fen, Sun, Lixian
• Format: Article
• Language: English
• Subjects: Hydrogen storage properties; Magnesium hydride; Nitrogen doping; Renewable energy
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.176975

MgH2 is thought to be the most promising solid hydrogen storage material because of its high mass hydrogen storage density (7.6 %), in addition to its good safety profile, high efficiency, and environmentally friendly nature. Nevertheless, the actual application of MgH2 is hindered by its slow kinetic characteristics and high working temperatures. This work reports the successful preparation of N-doped LaTiO3 (N-LTO) by a straightforward hydrothermal calcination process, followed by doping into MgH2 to improve its hydrogen storage properties. The incorporation of 7 wt% N-LTO reduced the initial dehydrogenation temperature of the MgH2 composite to 193 °C, and it was found that the composite rapidly release ∼6.2 wt% H2 within 5 min at 300 °C. During the rehydrogenation tests, the composite absorbed ∼4.7 wt% H2 under a 20 bar pressure of H2 at a low temperature of 50 °C, reflecting a significant improvement in the kinetic performance of H2 absorption/release from MgH2. This improved hydrogen storage performance can be attributed to the increased electron density on the surface of the material following nitrogen doping, which promotes its reactivity. Moreover, the electron transfer taking place between multivalent titanium ions during hydrogenation facilitates breakage of the Mg–H bond, which promotes the dissociation and recombination of hydrogen, thereby improving the kinetic properties of the material. ●N-doped LaTiO3 (N-LTO) was prepared via hydrothermal calcination.●The incorporation of 7 wt% N-LTO into MgH2 reduced the dehydrogenation temperature.●The composite release ∼6.2 wt% H2 within 5 min at 300 °C.●During rehydrogenation, the composite absorbed ∼4.7 wt% H2 under 20 bar H2 at 50 °C.●The mechanism of this improved hydrogen storage performance was deduced.