Application of Alumina Aerogels as Catalysts

Hiroshi Hirashima, Chihiro Kojima, Hiroaki Imai

Research output: Contribution to journalArticle

42 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
Publication statusPublished - 1997

Fingerprint

Aerogels
Aluminum Oxide
aerogels
Alumina
aluminum oxides
catalysts
Xerogels
Catalysts
xerogels
Gels
gels
Annealing
drying
annealing
Drying
autoclaves
Autoclaves
alkoxides
Hydrocarbons
Specific surface area

Keywords

  • Aerogel
  • AlO
  • Catalyst
  • Reduction of NO

ASJC Scopus subject areas

  • Ceramics and Composites

Cite this

Application of Alumina Aerogels as Catalysts. / Hirashima, Hiroshi; Kojima, Chihiro; Imai, Hiroaki.

In: Journal of Sol-Gel Science and Technology, Vol. 8, No. 1-3, 1997, p. 843-846.

Research output: Contribution to journalArticle

Hirashima, H, Kojima, C & Imai, H 1997, 'Application of Alumina Aerogels as Catalysts', Journal of Sol-Gel Science and Technology, vol. 8, no. 1-3, pp. 843-846.
Hirashima, Hiroshi ; Kojima, Chihiro ; Imai, Hiroaki. / Application of Alumina Aerogels as Catalysts. In: Journal of Sol-Gel Science and Technology. 1997 ; Vol. 8, No. 1-3. pp. 843-846.
@article{559ea2c24041485db4da770f6bdfbd90,
title = "Application of Alumina Aerogels as Catalysts",
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.",
keywords = "Aerogel, AlO, Catalyst, Reduction of NO",
author = "Hiroshi Hirashima and Chihiro Kojima and Hiroaki Imai",
year = "1997",
language = "English",
volume = "8",
pages = "843--846",
journal = "Journal of Sol-Gel Science and Technology",
issn = "0928-0707",
publisher = "Springer Netherlands",
number = "1-3",

}

TY - JOUR

T1 - Application of Alumina Aerogels as Catalysts

AU - Hirashima, Hiroshi

AU - Kojima, Chihiro

AU - Imai, Hiroaki

PY - 1997

Y1 - 1997

N2 - 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.

AB - 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.

KW - Aerogel

KW - AlO

KW - Catalyst

KW - Reduction of NO

UR - http://www.scopus.com/inward/record.url?scp=0030714861&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030714861&partnerID=8YFLogxK

M3 - Article

VL - 8

SP - 843

EP - 846

JO - Journal of Sol-Gel Science and Technology

JF - Journal of Sol-Gel Science and Technology

SN - 0928-0707

IS - 1-3

ER -