Dehydroaromatization of methane over Sn-Pt modified Mo/H-ZSM-5 zeolite catalysts

Effect of preparation method

Themba E. Tshabalala, Neil J. Coville, James A. Anderson, Michael S. Scurrell*

*Corresponding author for this work

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The effect of different catalyst preparation methods to make tin-platinum modified Mo/H-ZSM-5 zeolite catalysts for methane dehydroaromatization at 700 °C was investigated. The catalysts were prepared by both incipient wetness co-impregnation and sequential impregnation and calcined at 500 °C for 6 h. Catalysts prepared by the co-impregnation method showed a good platinum dispersion (10.8%), higher than found for the Pt/Sn and Sn/Pt sequentially impregnated catalysts (5.6% and 1.4%, respectively). Successive calcination treatments influenced the location of both tin and platinum in the catalyst and a decrease in platinum dispersion after reduction was evident from CO chemisorption studies. The order of sequentially loading platinum before or after tin had an effect on the electronic and structural properties of platinum as shown by XPS and FTIR studies. Different catalytic activities and aromatic selectivities were observed for the Pt/Sn and Sn/Pt catalysts. The co-impregnated Sn-Pt and the sequentially impregnated Pt/Sn catalysts showed high aromatic selectivity (>70%) and low coke selectivity (<20%). The decrease in coke selectivity is mainly dependent on the availability of platinum sites for hydrogenation of carbonaceous species.

Original languageEnglish
Pages (from-to)218-226
Number of pages9
JournalApplied Catalysis A: General
Volume503
Early online date3 Jul 2015
DOIs
Publication statusPublished - 25 Aug 2015

Fingerprint

Methane
Platinum
Catalysts
Tin
Impregnation
Catalyst selectivity
Coke
ZSM-5 zeolite
Carbon Monoxide
Chemisorption
Electronic properties
Calcination
Hydrogenation
Structural properties
Catalyst activity
X ray photoelectron spectroscopy
Availability

Keywords

  • H-ZSM-5
  • Methane dehydroaromatization
  • Molybdenum
  • Platinum
  • Tin

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Dehydroaromatization of methane over Sn-Pt modified Mo/H-ZSM-5 zeolite catalysts : Effect of preparation method. / Tshabalala, Themba E.; Coville, Neil J.; Anderson, James A.; Scurrell, Michael S.

In: Applied Catalysis A: General, Vol. 503, 25.08.2015, p. 218-226.

Research output: Contribution to journalArticle

Tshabalala, Themba E. ; Coville, Neil J. ; Anderson, James A. ; Scurrell, Michael S. / Dehydroaromatization of methane over Sn-Pt modified Mo/H-ZSM-5 zeolite catalysts : Effect of preparation method. In: Applied Catalysis A: General. 2015 ; Vol. 503. pp. 218-226.
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abstract = "The effect of different catalyst preparation methods to make tin-platinum modified Mo/H-ZSM-5 zeolite catalysts for methane dehydroaromatization at 700 °C was investigated. The catalysts were prepared by both incipient wetness co-impregnation and sequential impregnation and calcined at 500 °C for 6 h. Catalysts prepared by the co-impregnation method showed a good platinum dispersion (10.8{\%}), higher than found for the Pt/Sn and Sn/Pt sequentially impregnated catalysts (5.6{\%} and 1.4{\%}, respectively). Successive calcination treatments influenced the location of both tin and platinum in the catalyst and a decrease in platinum dispersion after reduction was evident from CO chemisorption studies. The order of sequentially loading platinum before or after tin had an effect on the electronic and structural properties of platinum as shown by XPS and FTIR studies. Different catalytic activities and aromatic selectivities were observed for the Pt/Sn and Sn/Pt catalysts. The co-impregnated Sn-Pt and the sequentially impregnated Pt/Sn catalysts showed high aromatic selectivity (>70{\%}) and low coke selectivity (<20{\%}). The decrease in coke selectivity is mainly dependent on the availability of platinum sites for hydrogenation of carbonaceous species.",
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