Self-regenerative activity of Ni/Mg(Al)O catalysts with trace Ru during daily start-up and shut-down operation of CH4 steam reforming

Dalin Li, Ikuo Atake, Tetsuya Shishido, Yasunori Oumi, Tsuneji Sano, Katsuomi Takehira

Research output: Contribution to journalArticle

88 Citations (Scopus)

Abstract

Ni/Mg(Al)O catalysts doped with trace Ru showed self-regenerative activity during a daily start-up and shut-down (DSS) operation of steam reforming of methane. Formation of Ru{single bond}Ni alloy on the surface of fine Ni metal particles on the catalysts was strongly suggested by EXAFS and TPR measurements. The Ni/Mg(Al)O catalyst was passivated by the oxidative incorporation of Ni0 to Ni2+ in Mg(Ni,Al)O periclase, and trace Ru assisted the regeneration of Ni metal from the Ni2+ by hydrogen spillover. Even notably sintered Ni metal particles on the Ni/Mg(Al)O catalyst by steaming were rapidly redispersed, resulting in the revelation of the high and stable activity during the DSS operation. The self-regeneration of the Ru{single bond}Ni/Mg(Al)O catalysts can be achieved by the continuous rebirth of active Ni metal species assisted cooperatively by both Ni2+ → Ni0 reduction by hydrogen-spillover via trace Ru metal or Ru{single bond}Ni alloy and reversible reduction-oxidation between Ni0 and Ni2+ in Mg(Ni,Al)O periclase.

Original languageEnglish
Pages (from-to)299-312
Number of pages14
JournalJournal of Catalysis
Volume250
Issue number2
DOIs
Publication statusPublished - 2007 Sep 10

Keywords

  • CH reforming
  • Daily start-up and shut-down operation
  • Memory effect
  • Ni/Mg(Al)O catalyst
  • Ru doping
  • Self-regeneration

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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