title: Cost-Effective Hierarchical Catalysts for Promoting Hydrogen Release from Complex Hydrides.
abstract: Fe nanoparticles (∼10 nm), used to grow carbon nanotubes (CNTs), have an outstanding ability to catalyze the dehydrogenation of LiAlH4 . The CNTs help connect Fe and LiAlH4 and create microchannels among the composite, thus promoting the release of hydrogen. Inspired by these results, a supercritical-CO2 -fluid-assisted deposition technique is employed to decorate the Fe/CNTs with highly dispersed nanosized Ni (∼2 nm in diameter) for better performance. With the incorporation of 10 wt % of this hierarchical catalyst (Ni/Fe/CNTs), the initial dehydrogenation temperature of LiAlH4 is decreased from ∼135 to ∼40 °C. At 100 °C, this catalyzed LiAlH4 takes only ∼0.1 h to release 4.5 wt % hydrogen, which is more than 100 times faster than the time needed with pristine LiAlH4 . The dehydrogenation mechanism of the complex hydride is examined using in situ synchrotron X-ray diffraction.
authors.affiliation: Institute of Materials Science and Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan), Fax: (+886) 3-2805034.
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Yang
authors.affiliation: Institute of Materials Science and Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan), Fax: (+886) 3-2805034.
authors.forename: Chih-Ping
authors.initials: CP
authors.lastname: Hsu
authors.affiliation: Institute of Materials Science and Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan), Fax: (+886) 3-2805034.
authors.forename: Sheng-Long
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Institute of Materials Science and Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan), Fax: (+886) 3-2805034.
authors.forename: Kuan-Wen
authors.initials: KW
authors.lastname: Wang
authors.affiliation: Institute of Materials Science and Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan), Fax: (+886) 3-2805034. jkchang@ncu.edu.tw.|Department of Chemical and Materials Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan). jkchang@ncu.edu.tw.|Department of Mechanical Engineering, National Central University, 300 Jhong-Da Road, Taoyuan (Taiwan). jkchang@ncu.edu.tw.
authors.forename: Jeng-Kuei
authors.initials: JK
authors.lastname: Chang
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D002384:Catalysis; D003362:Cost-Benefit Analysis; D006108:Graphite / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D018020:Lithium Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D009532:Nickel / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D018020:Lithium Compounds; D037742:Nanotubes, Carbon; D006108:Graphite; C042073:lithium aluminum hydride; D009532:Nickel; D006859:Hydrogen; D007501:Iron
keywords: hierarchical catalysts; hydrides; nanotubes; supercritical fluid; x-ray diffraction