title: Hydrogenation properties of mechanically milled Mg2Ni0.8Cr0.2-CoO/Al2O3 composites.
abstract: Mg2Ni0.8Cr0.2-x wt.% CoO/Al2O3 (x=0.5, 1, 2 and 3) composites were prepared by mechanically milling sintered Mg2Ni0.8Cr0.2 alloy and CoO/Al2O3 compound for 45 h. The addition of CoO/Al2O3 compound resulted in the good kinetics properties of hydriding/dehydriding reaction of the composites. The composite with 1.0 wt.% CoO/Al2O3 catalyst could reach the maximum hydrogen absorption capacity (2.9 wt.%) within 5 min at 393 K under H2 pressure of 4 MPa, and can desorb rapidly at 493 K. The decomposition and synthesis of hydrogen molecule on Mg2Ni0.8Cr0.2 alloy surface was promoted by addition of CoO/Al2O3 catalyst. In addition, the formation of metallic Ni particles, strain and defects during the ball milling process also resulted in the improved hydrogenation performance of Mg2Ni-based alloys.
authors.affiliation: Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Jiang-Ping
authors.initials: JP
authors.lastname: Tu
authors.forename: Chang-Pin
authors.initials: CP
authors.lastname: Chen
authors.forename: Xiao-Bin
authors.initials: XB
authors.lastname: Zhang
authors.forename: Xin-Bing
authors.initials: XB
authors.lastname: Zhao
mesh_terms: D000042:Absorption; D000537:Aluminum Oxide / Q000032:analysis / Q000737:chemistry*; D006358:Hot Temperature; D006859:Hydrogen / Q000032:analysis / Q000737:chemistry*; D007700:Kinetics; D017616:Magnesium Compounds / Q000032:analysis / Q000737:chemistry*; D008420:Manufactured Materials / Q000032:analysis*; D008422:Materials Testing; D008968:Molecular Conformation; D017672:Nitrogen Compounds / Q000032:analysis / Q000737:chemistry*; D011312:Pressure; D013696:Temperature
chemical_list: D017616:Magnesium Compounds; D017672:Nitrogen Compounds; D006859:Hydrogen; D000537:Aluminum Oxide