title: Formation of Multiple-Phase Catalysts for the Hydrogen Storage of Mg Nanoparticles by Adding Flowerlike NiS.
abstract: In order to enhance the hydrogen storage properties of Mg, flowerlike NiS particles have been successfully prepared by solvothermal reaction method, and are subsequently ball milled with Mg nanoparticles (NPs) to fabricate Mg-5 wt % NiS nanocomposite. The nanocomposite displays Mg/NiS core/shell structure. The NiS shell decomposes into Ni, MgS and Mg2Ni multiple-phases, decorating on the surface of the Mg NPs after the first hydrogen absorption and desorption cycle at 673 K. The Mg-MgS-Mg2Ni-Ni nanocomposite shows enhanced hydrogenation and dehydrogenation rates: it can quickly uptake 3.5 wt % H2within 10 min at 423 K and release 3.1 wt % H2within 10 min at 573 K. The apparent hydrogen absorption and desorption activation energies are decreased to 45.45 and 64.71 kJ mol-1. The enhanced sorption kinetics of the nanocomposite is attributed to the synergistic catalytic effects of the in situ formed MgS, Ni and Mg2Ni multiple-phase catalysts during the hydrogenation/dehydrogenation process, the porthole effects for the volume expansion and microstrain of the phase transformation of Mg2Ni and Mg2NiH4and the reduced hydrogen diffusion distance caused by nanosized Mg. This novel method of in situ producing multiple-phase catalysts gives a new horizon for designing high performance hydrogen storage material.
authors.affiliation: Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University , No.37 Xueyuan Road, Beijing, 100191, China.
authors.forename: Xiubo
authors.initials: X
authors.lastname: Xie
authors.affiliation: Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University , No.37 Xueyuan Road, Beijing, 100191, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Ma
authors.affiliation: Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University , No.37 Xueyuan Road, Beijing, 100191, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University , No.37 Xueyuan Road, Beijing, 100191, China.
authors.forename: Jiaxiang
authors.initials: J
authors.lastname: Shang
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), The State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University , No.37 Xueyuan Road, Beijing, 100191, China.
authors.forename: Tong
authors.identifier: http://orcid.org/0000-0002-1079-3169
authors.initials: T
authors.lastname: Liu
keywords: catalytic effects; hydrogen storage; magnesium; multiple-phase catalysts; nanocomposite