High combustion activity of methane induced by reforming gas over Ni/Al2O3 catalysts

Baitao Li, Ritsuko Watanabe, Kenji Maruyama, Mohammad Nurunnabi, Kimio Kunimori, Keiichi Tomishige

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)

Abstract

During the reactions related to oxidative steam reforming and combustion of methane over α-alumina-supported Ni catalysts, the temperature profiles of the catalyst bed were studied using an infrared (IR) thermograph. IR thermographical images revealed an interesting result: that the temperature at the catalyst bed inlet is much higher under CH4/H 2O/O2/Ar = 20/10/20/50 than under CH4/H 2O/O2/Ar = 10/0/20/70; the former temperature is comparable to that over noble metal catalysts such as Pt and Pd. Based on the temperature-programmed reduction and oxidation measurements over fresh and used catalysts, the metallic Ni is recognized at the catalyst bed inlet under CH 4/H2O/O2/Ar = 20/10/20/50, although it is mainly oxidized to NiAl2O4 under CH4/H 2O/O2/Ar = 10/0/20/70. This result indicates that the addition of reforming gas (CH4/H2O = 10/10) to the combustion gas (CH4/O2 = 10/20) can stabilize Ni species in the metallic state even under the presence of oxygen in the gas phase. This would account for its extremely high combustion activity.

Original languageEnglish
Pages (from-to)36-45
Number of pages10
JournalApplied Catalysis A: General
Volume290
Issue number1-2
DOIs
Publication statusPublished - 2005 Aug 18
Externally publishedYes

Keywords

  • Combustion
  • Hot spot
  • Methane
  • Oxidative steam reforming
  • Temperature-programmed oxidation
  • Temperature-programmed reduction
  • Thermography

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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