• Qi Wan

      Articles written in Bulletin of Materials Science

    • NbCl5 and CrCl3 catalysts effect on synthesis and hydrogen storage performance of Mg–Ni–NiO composites

      Qi Wan Ping Li Teng Wang Xuanhui Qu Fuqiang Zhai Alex A Volinsky Philip J Logan

      More Details Abstract Fulltext PDF

      Two kinds of novel materials, Mg–1.6 mol% Ni–0.4 mol% NiO–2 mol% MCl (MCl = NbCl5, CrCl3), along with Mg–1.6 mol% Ni–0.4 mol% NiO for comparison, were examined for their potential use in hydrogen storage applications, having been fabricated via cryomilling. The effects of NbCl5 and CrCl3 on hydrogen storage performance were investigated. A microstructure analysis showed that besides the main Mg and Ni phases, NiO and Mg2Ni phases were present in all samples. MgCl2 was only found in halide-doped samples and NbO was only found in NbCl5-doped samples after ball milling. The particle size decreased significantly after 7 h of cryomilling. MgH2, Mg2NiH4 and Mg2NiH0.3 were present in all the samples, while NbH2 was only observed in the NbCl5 -doped sample after absorption. The NbCl5-containing composite exhibited a low onset absorption temperature of 323 K, which was 10 K lower than that of the no-halide doped catalyst. It absorbed 5.32 wt% of hydrogen in 370 s at 623 K under 4 MPa hydrogen pressure and can absorb 90% of its full hydrogen capacity in 50 s. Having an onset desorption temperature of 483 K in vacuum, the NbCl5 -containing composite desorbed hydrogen faster than the no-halide doped sample. The hydriding–dehydriding kinetics performance of the CrCl3-doped sample did not improve, but it did exhibit a lower onset desorption temperature of 543 K under 0.1 MPa, which was 20 K lower than that of the no-halide doped sample. NbO, NiO and NbH2 played important roles in improving absorption and desorption performances.

    • CO impurities effect on LaNi4.7Al0.3 hydrogen storage alloy hydrogenation/dehydrogenation properties

      Qi Wan Ping Li Yunlong Li Fuqiang Zhai Weina Zhang Liqun Cui Alex A Volinsky Xuanhui Qu

      More Details Abstract Fulltext PDF

      LaNi4.7Al0.3 alloy was prepared by vacuum induction melting in high purity helium atmosphere, and the ingot was pulverized into 200–400 mesh powder after annealing. X-ray diffraction (XRD) and scanning electron microscopies (SEM) were utilized to study the alloy morphology and phase structure. X-ray photoelectron spectroscopy (XPS) was used for surface analysis. The poisoned alloy was tested at 30 °C in the mixture gas by thermogravimetric and differential thermal analyses (TG + DTA). The hydrogen storage properties were studied by the pressure–composition–temperature test. The activated sample was completely deactivated after only 3 hydriding/dehydriding cycles in hydrogen containing 300 ppm CO at 30 °C, but hydrogen storage capacity did not degrade when tested at 80 °C. Additionally, two different steps appeared in the absorption processes. Combined with XRD, XPS and TG + DTA results, an explanation for this phenomenon is given.

  • Bulletin of Materials Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.