NO was adsorbed on Cu-ZSM-5 at temperatures between 173 K < T < 73K. The IR spectra indicated that three types of adsorbed NO species are formed: NOᵟ+ (1900 cm-1), NOᵟ− (1810 cm-1) and dimeric or dinitrosyl (NO)2 (1824 cm-1 and 1730 cm-1). Disproportionation of NO at low temperature produced N2O and NO2. Bands stemming from adsorption of these species were also observed. It was found that an equilibrium exists between the NOᵟ- and (NO)2 species bound to reduced Cu sites. The results suggest that the same (NO)2 species which is a possible intermediate in NO disproportionation at low temperature (≤ 298 K) can be a transient state in NO decomposition at high temperature (> 600 K).
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry