Characterization of SnO 2/Al 2O 3 lean NO x catalysts

P. W. Park, Harold H Kung, D. W. Kim, M. C. Kung

Research output: Contribution to journalArticle

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Abstract

SnO 2/Al 2O 3 prepared with SnCl 2 impregnation onto sol-gel Al 2O 3 and calcined at 800°C is one of the most active catalysts for lean NO x reduction with propene under high partial pressures of O 2 (15%) and H 2O (10%) and space velocity (30,000 h -1). An unusual feature of this catalyst is the independence of maximum NO conversion over a wide range of Sn contents (1 to 10 wt% Sn). This catalyst is, however, sensitive to other preparation variables such as the nature of Sn precursor and the calcination temperature. X-ray photoelectron spectroscopic results indicate that Sn is present in the +4 oxidation state irrespective of Sn loadings. X-ray diffraction, temperature-programmed desorption, and temperature-programmed reduction results indicate a wide range of oxo-tin cluster sizes as well as different ratios of amorphous and crystalline SnO 2 present in samples with different Sn loadings. The Sn(IV) in the amorphous SnO 2 fraction can be reduced to Sn(II) below 450°C in the TPR experiments. In fact, all of the SnO 2/Al 2O 3 catalysts have very similar H 2 uptake features below 450°C. In view of the fact that they also have very similar catalytic properties, it appears likely that easily reducible amorphous SnO 2 is an active phase for lean NO x catalysis in these samples.

Original languageEnglish
Article numberjcat.1999.2459
Pages (from-to)440-454
Number of pages15
JournalJournal of Catalysis
Volume184
Issue number2
Publication statusPublished - 1999

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catalysts
Catalysts
Tin
Temperature programmed desorption
Photoelectrons
Impregnation
Partial pressure
Calcination
roasting
Catalysis
Propylene
catalysis
Sol-gels
partial pressure
temperature
tin
photoelectrons
x rays
desorption
gels

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Park, P. W., Kung, H. H., Kim, D. W., & Kung, M. C. (1999). Characterization of SnO 2/Al 2O 3 lean NO x catalysts. Journal of Catalysis, 184(2), 440-454. [jcat.1999.2459].

Characterization of SnO 2/Al 2O 3 lean NO x catalysts. / Park, P. W.; Kung, Harold H; Kim, D. W.; Kung, M. C.

In: Journal of Catalysis, Vol. 184, No. 2, jcat.1999.2459, 1999, p. 440-454.

Research output: Contribution to journalArticle

Park, PW, Kung, HH, Kim, DW & Kung, MC 1999, 'Characterization of SnO 2/Al 2O 3 lean NO x catalysts', Journal of Catalysis, vol. 184, no. 2, jcat.1999.2459, pp. 440-454.
Park PW, Kung HH, Kim DW, Kung MC. Characterization of SnO 2/Al 2O 3 lean NO x catalysts. Journal of Catalysis. 1999;184(2):440-454. jcat.1999.2459.
Park, P. W. ; Kung, Harold H ; Kim, D. W. ; Kung, M. C. / Characterization of SnO 2/Al 2O 3 lean NO x catalysts. In: Journal of Catalysis. 1999 ; Vol. 184, No. 2. pp. 440-454.
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