Topics in Catalysis

, Volume 16, Issue 1, pp 151–155

The Mechanism of the Selective NOx Sorption on H3PW12O40·6H2O (HPW)

Authors

  • S. Hodjati
    • LERCSI, Laboratoire d'Etudes de la Réactivité Catalytique, Surfaces et Interfaces, UMR 7515 du CNRS - ECPM
  • K. Vaezzadeh
    • LERCSI, Laboratoire d'Etudes de la Réactivité Catalytique, Surfaces et Interfaces, UMR 7515 du CNRS - ECPM
  • C. Petit
    • LERCSI, Laboratoire d'Etudes de la Réactivité Catalytique, Surfaces et Interfaces, UMR 7515 du CNRS - ECPM
  • V. Pitchon
    • LERCSI, Laboratoire d'Etudes de la Réactivité Catalytique, Surfaces et Interfaces, UMR 7515 du CNRS - ECPM
  • A. Kiennemann
    • LERCSI, Laboratoire d'Etudes de la Réactivité Catalytique, Surfaces et Interfaces, UMR 7515 du CNRS - ECPM
Article

DOI: 10.1023/A:1016655519790

Cite this article as:
Hodjati, S., Vaezzadeh, K., Petit, C. et al. Topics in Catalysis (2001) 16: 151. doi:10.1023/A:1016655519790

Abstract

NOx absorption/desorption capacities of 12-tungstophosphoric acid hexa-hydrate were measured under representative exhaust gas mixture conditions. The amounts of NOx absorbed and then desorbed are high and equal to 46 of NO2 mgg−1 of HPW. The mechanism of absorption proceeds by substitution of lattice water molecules with formation of a [H+(NO2,NO+)] complex. During the cooling phase and in the presence of water, around 100°C, reverse substitution occurs. Two possibilities to wash-coat HPW on a monolith are presented. The first one consists in a partial substitution of H+ by a monovalent cation while the second one consists of supporting HPW on a high surface oxide. The anchorage quality is related to the Brønsted acidity, the best candidates for the role of support are SnO2 and TiO2.

NOx storagelean-burntungstophosphoric acid

Copyright information

© Plenum Publishing Corporation 2001