Application of Alumina Aerogels as Catalysts

Hiroshi Hirashima, Chihiro Kojima, Hiroaki Imai

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47 Citations (Scopus)

Abstract

Al2O3 gels prepared by hydrolysis of Al-alkoxide were applied as catalysts for NO reduction by hydrocarbon. Xerogels were obtained by drying at 90°C, for 24 h, in air. Aerogels were prepared by supercritical drying of the wet gels in ethanol, using an autoclave. The catalyst activity of the gels for NO reduction with C3H6 as determined at 200-600°C in a fixed bed flow reactor. NO conversion to N2 was about 60% at 550°C with both catalysts, and at 600°C it was better with the aerogel than with the xerogel. The specific surface area of the xerogel, which was larger than that of the aerogel as-dried, decreased to 1/3 by annealing at >500°C. However, the surface area of the aerogel hardly changed by annealing at temperatures up to 700°C. The bimodal pore size distribution of the aerogel hardly changed by annealing, too. The microstructure of the aerogels is stable at high temperatures, and they are better catalysts at high temperatures.

Original languageEnglish
Pages (from-to)843-846
Number of pages4
JournalJournal of Sol-Gel Science and Technology
Volume8
Issue number1-3
DOIs
Publication statusPublished - 1997 Jan 1

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Keywords

  • Aerogel
  • AlO
  • Catalyst
  • Reduction of NO

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Chemistry(all)
  • Biomaterials
  • Condensed Matter Physics
  • Materials Chemistry

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