Anomalous hydrogen absorption on non-stoichiometric iron-carbon compound

Hiroki Miyaoka, Takayuki Ichikawa, Tatsuo Fujii, Wataru Ishida, Shigehito Isobe, Hironobu Fuji, Yoshitsugu Kojima

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


On the synthesis of nano-structural hydrogenated graphite by ball-milling under H2 atmosphere, iron contamination was mingled from steel balls during ball-milling. It is clarified by spectroscopic measurements that the mingled iron formed a non-stoichiometric iron-carbon (Fe-C) compound. The Fe-C phase was transformed to a well-ordered phase with H2 desorption at 450 °C, suggesting that the hydrogen atoms were anomalously trapped at the Fe-C phase. With respect to hydrogen absorbing properties, the mingled iron enhanced the hydrogen capacity by about 50% compared with iron free hydrogenated graphite, where H/Fe was about 13 mass%. Therefore, if the hydrogen absorption site originated in the Fe-C phase could be synthesized independently, it should be recognized as a promising hydrogen storage system.

Original languageEnglish
Pages (from-to)547-550
Number of pages4
JournalJournal of Alloys and Compounds
Issue number2
Publication statusPublished - Oct 8 2010


  • Amorphous materials
  • Hydrogen absorbing materials
  • Mechanochemical processing
  • Mössbauer spectroscopy
  • Thermal analysis
  • X-ray and gamma-ray spectroscopies

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


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