A bifunctional catalyst for the single-stage water-gas shift reaction in fuel cell applications. Part 2. Roles of the support and promoter on catalyst activity and stability.

K.G.H. Azzam, Igor V. Babych, Kulathuiyer Seshan, Leonardus Lefferts

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Abstract

The nature of oxide supports has a crucial effect on the performance of Pt-based catalysts in the water–gas shift reaction. Supports not only determine the activity of the catalyst, but also influence their stability (deactivation mechanism). Among the catalysts studied, Pt/TiO2 was the most active. Pt/CeO2 deactivated with time due to the formation of stable carbonate on the ceria surface. Sintering of Pt was found to be the cause of Pt/TiO2 deactivation. Using mixed oxides as catalyst supports did not improve the activity despite the better red–ox properties of mixed oxides compared with the single-oxide supports. Pt/TiO2 could be stabilized by adding a second metal (Re), which prevented Pt sintering. In addition, Pt–Re/TiO2 was more active than Pt/TiO2. Under WGS conditions, part of the Re was present in oxidizing form (ReOx); we speculate that this helped improve the catalyst activity.
Original languageUndefined
Pages (from-to)163-171
Number of pages9
JournalJournal of catalysis
Volume251
Issue number1
DOIs
Publication statusPublished - 2007

Keywords

  • TiN
  • Platinum
  • Oxide supports
  • Stability
  • WGS reaction
  • Deactivation
  • METIS-244071
  • Rhenium
  • Activity
  • IR-78815

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