Influence of modification method and transition metal type on the physicochemical properties of MCM-41 catalysts and their performances in the catalytic ozonation of toluene

Maoshuai Li, K. N. Hui, K. S. Hui, S. K. Lee, Y. R. Cho, Heesoo Lee, W. Zhou, Shinho Cho, C. Y. H. Chao, Yangyang Li

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The current study describes the catalytic ozonation of toluene using MCM-41 catalysts modified by different transition metals (Cu and Co) and methods (in situ synthesis and impregnation). The characteristic hexagonal channel array of the MCM-41 pore system was not destroyed by the transition metal modification, but the order and surface area were decreased. Large particles of copper oxide exposed on the (1. 1. 1) lattice plane, which were indicative of severe sintering, were found on the catalyst modified by Cu via in situ synthesis. Such particles were not observed on the other catalysts. Using the modified catalysts in toluene ozonation revealed that with increased reaction temperature, toluene conversion under a steady state increased, whereas ozone conversion decreased. The transition metal-modified MCM-41s also had largely improved catalytic activities compared with pure MCM-41. Catalytic performance was found to depend on the metal type and modification method. The method that resulted in improved catalytic performance was in situ synthesis for the Co-modified MCM-41, and was impregnation for the Cu-modified MCM-41. The relatively superior performance of the transition metal-modified catalysts over pure MCM-41 is attributed to two main features. One is the well dispersion of metal oxides, and the other is the strong capacity to decompose built-up organic byproducts on the catalyst surface.

Original languageEnglish
Pages (from-to)245-252
Number of pages8
JournalApplied Catalysis B: Environmental
Volume107
Issue number3-4
Early online date23 Jul 2011
DOIs
Publication statusPublished - 21 Sep 2011

Keywords

  • Catalytic oxidation
  • MCM-41
  • Ozone
  • Toluene
  • Transition metal

Cite this