Influence of oxidation on the stability of Pt-Co bimetallic particles entrapped in NaY-zeolite

Genmin Lu, L. Guczi

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Temperature-programmed reduction and desorption (TPR, TPD) have been applied tostudy the stability of Pt-Co bimetallic particles entrapped in NaY zeolite cages upon O2 oxidation and reaction with surface protons generated during the reduction of transition metal cations. Oxidation of Pt/NaY catalyst with O2 at 573 K causes shift of TPR peak to lower temperature due to formation of partially oxidized Pt particles. Similar treatment for Pt-Co/NaY bimetallic catalysts results in complete isolation of Pt and Co in Pt-Co particles, leaving Pt and Co in supercages and sodalite cages, respectively. Under inert atmosphere Co can also be leached out from Pt-Co bimetallic particles at higher temperature by reacting with surface protons. The results present further evidences that oxidized Co ions are driven into small cages, whereas Pt particles remain in the supercages. Although oxidation of Co at temperature lower than 723 K could not be excluded, the hydrogen evolution peak in the temperature range of 470-770 K may be considered as the desorption of activated H2 on Co in Pt-Co bimetallic particles. The results are consistent with previous suggestion that interaction of Pt and Co precursors in calcined Pt-Co/NaY catalyst is essential for Pt catalyzed Co reduction and bimetallic particle formation.

Original languageEnglish
Pages (from-to)171-178
Number of pages8
JournalStudies in Surface Science and Catalysis
Volume94
Issue numberC
DOIs
Publication statusPublished - 1995

Fingerprint

Zeolites
Oxidation
oxidation
Catalysts
Protons
Desorption
Temperature
catalysts
desorption
sodalite
Transition metals
Cations
Hydrogen
inert atmosphere
protons
Positive ions
Ions
suggestion
isolation
transition metals

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Catalysis
  • Physical and Theoretical Chemistry
  • Materials Chemistry
  • Surfaces, Coatings and Films

Cite this

Influence of oxidation on the stability of Pt-Co bimetallic particles entrapped in NaY-zeolite. / Lu, Genmin; Guczi, L.

In: Studies in Surface Science and Catalysis, Vol. 94, No. C, 1995, p. 171-178.

Research output: Contribution to journalArticle

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