Rod-, flower-, and dumbbell-like MnO 2: Highly active catalysts for the combustion of toluene

Fengjuan Shi, Fang Wang, Hongxing Dai*, Jianxing Dai, Jiguang Deng, Yuxi Liu, Guangmei Bai, Kemeng Ji, Chak Tong AU

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

93 Citations (Scopus)

Abstract

The rod-like tetragonal α-MnO 2, flower-like hexagonal ε-MnO 2, and dumbbell-like tetragonal β-MnO 2 were prepared using the hydrothermal or water-bathing method under different conditions. It is shown that the α-MnO 2, ε-MnO 2, and β-MnO 2 catalysts possessed a surface area of ca. 53, 30, and 114 m 2/g, respectively. The oxygen adspecies concentration and low-temperature reducibility decreased in the order of α-MnO 2 > ε-MnO 2 > β-MnO 2, coinciding with the sequence of their catalytic activities for toluene combustion. The well-defined morphological MnO 2 catalysts performed much better than the bulk counterpart. At a space velocity of 20,000 mL/(g h), the temperature for 90% toluene conversion was 238, 229, and 241 °C over α-MnO 2, ε-MnO 2, and β-MnO 2, respectively. The apparent activation energies of α-MnO 2, ε-MnO 2, and β-MnO 2 were in the range of 20-26 kJ/mol. It is concluded that higher oxygen adspecies concentrations and better low-temperature reducibility were responsible for the good catalytic performance of the α-MnO 2, ε-MnO 2, and β-MnO 2 materials.

Original languageEnglish
Pages (from-to)206-213
Number of pages8
JournalApplied Catalysis A: General
Volume433-434
DOIs
Publication statusPublished - 8 Aug 2012

Scopus Subject Areas

  • Catalysis
  • Process Chemistry and Technology

User-Defined Keywords

  • Hydrothermal preparation method
  • Manganese oxide catalyst
  • Toluene combustion
  • Water-bathing preparation method
  • Well-defined morphology

Fingerprint

Dive into the research topics of 'Rod-, flower-, and dumbbell-like MnO <sub>2</sub>: Highly active catalysts for the combustion of toluene'. Together they form a unique fingerprint.

Cite this