Selectivity changes due to restructuring of the Pt(533) surface in the NH3 + O2 reaction

A. Scheibe, S. Günther, R. Imbihl

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Ammonia oxidation with oxygen over Pt(533) in the pressure range 10 -7-10-3mbar has been studied using LEED and scanning tunneling microscopy (STM) to detect reaction-induced structural changes. Below 620 K, strong hysteresis effects in the rate occur upon cyclic variation of one of the p, T parameters. The rate changes are associated with structural modifications of the substrate. The Pt(533) surface exhibiting single atomic steps after preparation undergoes a doubling in step height and terrace width connected with a shift in selectivity from preferential N2 production to strong NO formation. Restoring the single atomic steps in vacuum requires heating above 1100 K, but under reaction conditions the substrate changes are reversible at least down to 600 K.

Original languageEnglish
Pages (from-to)33-37
Number of pages5
JournalCatalysis Letters
Volume86
Issue number1-3
DOIs
StatePublished - Mar 2003
Externally publishedYes

Keywords

  • Ammonia oxidation
  • Catalyst restructuring
  • Hysteresis effects
  • Scanning tunneling microscopy
  • Stepped Pt surface

Fingerprint

Dive into the research topics of 'Selectivity changes due to restructuring of the Pt(533) surface in the NH3 + O2 reaction'. Together they form a unique fingerprint.

Cite this