skip to main content


Title: New operation strategy for driving the selectivity of NO x reduction to N 2, NH 3 or N 2O during lean/rich cycling of a lean NO x trap catalyst

Periodical regeneration of NO x storage catalyst (also known as lean NO x trap) by short rich pulses of CO, H 2 and hydrocarbons is necessary for the reduction of nitrogen oxides adsorbed on the catalyst surface. Ideally, the stored NO x is converted into N 2, but N 2O and NH 3 by-products can be formed as well, particularly at low-intermediate temperatures. The N 2 and N 2O products are formed concurrently in two peaks. The primary peaks appear immediately after the rich-phase inception, and tail off with the breakthrough of the reductant front accompanied by NH 3 product. In addition, the secondary N 2 and N 2O peaks then appear at the rich-to-lean transition as a result of reactions between surface-deposited reductants/intermediates (CO, HC, NH 3, — NCO) and residual stored NO x under increasingly lean conditions.
 [1] ;  [1] ;  [2] ;  [2]
  1. Univ. of Chemistry and Technology, Prague (Czech Republic)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Applied Catalysis. B, Environmental
Additional Journal Information:
Journal Volume: 182; Journal Issue: C; Journal ID: ISSN 0926-3373
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; NOx storage catalysts; lean NOx trap; NOx reduction; N2O formation; LNT; NSR; exhaust gas aftertreatment; automotive catalysts
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1396941