Coordination structures of vanadium and iron in MCM-41 and the catalytic properties in partial oxidation of methane

Qinghong Zhang, Wei Yang, Xiaoxing Wang, Ye Wang, Tetsuya Shishido, Katsuomi Takehira

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

The coordination structures of vanadium and iron introduced into MCM-41, a typical mesoporous silica, by both direct hydrothermal synthesis (DHT) and template-ion exchange (TIE) methods have been studied by X-ray absorption spectroscopy (XANES and EXAFS). Vanadium is tetrahedrally coordinated with oxygen in V-MCM-41 prepared by both methods but the location of vanadium is probably different; vanadium is mainly incorporated inside the framework of MCM-41 by the DHT method as the content is lower than approximately 1 wt%, while the vanadyl tetrahedra are probably dispersed on the wall surface of MCM-41 over the samples by the TIE method. In the case of Fe-MCM-41, the DHT method results in iron atoms mainly in tetrahedral coordination and isolated from each other in the framework of MCM-41. However, aggregated iron oxides with iron in octahedral coordination are mainly observed in the TIE samples. The V-MCM-41 by the TIE method shows better catalytic performances than that by the DHT method in the partial oxidation of methane to formaldehyde with oxygen. However, the Fe-MCM-41 by the DHT method exhibits remarkably higher methane conversion and formaldehyde selectivity than that by the TIE method.

Original languageEnglish (US)
Pages (from-to)223-234
Number of pages12
JournalMicroporous and Mesoporous Materials
Volume77
Issue number2-3
DOIs
StatePublished - Jan 26 2005

Fingerprint

Vanadium
Methane
Multicarrier modulation
vanadium
templates
methane
Iron
Hydrothermal synthesis
iron
Oxidation
oxidation
synthesis
Ion exchange
ions
formaldehyde
Formaldehyde
oxygen
iron oxides
tetrahedrons
Oxygen

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials

Cite this

Zhang, Qinghong ; Yang, Wei ; Wang, Xiaoxing ; Wang, Ye ; Shishido, Tetsuya ; Takehira, Katsuomi. / Coordination structures of vanadium and iron in MCM-41 and the catalytic properties in partial oxidation of methane. In: Microporous and Mesoporous Materials. 2005 ; Vol. 77, No. 2-3. pp. 223-234.
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Coordination structures of vanadium and iron in MCM-41 and the catalytic properties in partial oxidation of methane. / Zhang, Qinghong; Yang, Wei; Wang, Xiaoxing; Wang, Ye; Shishido, Tetsuya; Takehira, Katsuomi.

In: Microporous and Mesoporous Materials, Vol. 77, No. 2-3, 26.01.2005, p. 223-234.

Research output: Contribution to journalArticle

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