caa a22 4500 463231392 CHVBK 20180405153243.0 cr unu---uuuuu 170326e20071201xx s 000 0 eng 10.1007/s10853-007-2037-4 doi (NATIONALLICENCE)springer-10.1007/s10853-007-2037-4 Effect of surface oxidation on the hydriding and dehydriding of Mg2Ni alloy produced by hydriding combustion synthesis [Elektronische Daten] [Dongming Liu, Yunfeng Zhu, Liquan Li] Hydriding combustion synthesis (HCS) has been regarded as an innovative process for the preparation of high active magnesium-based hydrogen storage alloys. For the purpose of understanding the interrelation of the unique hydrogen storage properties and the surface characteristics of the HCS product, the samples of Mg2Ni alloy/hydride with and without exposure to air were prepared from the HCS product of Mg2NiH4. The hydriding and dehydriding properties were compared and the surface compositions were analyzed by means of X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES). It was shown that the air exposure considerably decreases the hydriding activity of Mg2Ni. Absorbing of 3.0wt.% of hydrogen under the conditions of 603K and 3.0MPa after the air exposure takes 1500s, which is six times longer than for the unexposed alloy. The hydrogen desorption of the hydride are also impeded by the air-exposure, which results in the increase of dehydriding temperature from 450K to 540K. XPS and AES analyses indicated that Mg segregates and exists in the form of hydroxide on the surface of the air-exposed sample, which is responsible for the degradation of the hydriding and dehydriding properties. It was confirmed that the fresh surfaces generated during the dehydriding process of the as-synthesized hydride product contributes to the high activity of the HCS product in the first cycle of the hydriding determination. Springer Science+Business Media, LLC, 2007 Liu Dongming College of Materials Science and Engineering, Nanjing University of Technology, 210009, Nanjing, P.R. China aut Zhu Yunfeng College of Materials Science and Engineering, Nanjing University of Technology, 210009, Nanjing, P.R. China aut Li Liquan College of Materials Science and Engineering, Nanjing University of Technology, 210009, Nanjing, P.R. China aut Journal of Materials Science Springer US; http://www.springer-ny.com 42/23(2007-12-01), 9725-9729 0022-2461 42:23<9725 2007 42 10853 https://doi.org/10.1007/s10853-007-2037-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-007-2037-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Liu Dongming College of Materials Science and Engineering, Nanjing University of Technology, 210009, Nanjing, P.R. China aut NATIONALLICENCE 700 1- Zhu Yunfeng College of Materials Science and Engineering, Nanjing University of Technology, 210009, Nanjing, P.R. China aut NATIONALLICENCE 700 1- Li Liquan College of Materials Science and Engineering, Nanjing University of Technology, 210009, Nanjing, P.R. China aut NATIONALLICENCE 773 0- Journal of Materials Science Springer US; http://www.springer-ny.com 42/23(2007-12-01), 9725-9729 0022-2461 42:23<9725 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer