Abstract
Fe/ZSM-5 catalysts prepared by sublimation of FeCl3 onto H/ZSM-5 catalyze the selective reduction of NOx by hydrocarbons to N2. The order of the relative rates and N2 yields obtained with different alkanes reveals a non-trivial chemistry. The maximum yield is lower for propane than for n-butane but about the same for n- and iso-butane. However, at temperatures below this maximum, the N2 yield is higher for propane and n-butane than for iso-butane. Deposits are formed on the catalyst that contain N atoms in a low-oxidation state which are able to react with NO2 to form N2. TPO and FTIR results show that the amount and also the character of the deposits depend on the nature of alkanes. The change of the oxidation state of nitrogen from a high value in NO or NO2 to a lower value in nitrile and amino groups of the deposit is rationalized by applying mechanistic concepts of organic chemistry, including the Beckmann rearrangement and fragmentation. FTIR spectra and the observed oxygen- and nitrogen-containing compounds by GC-MS are potential clues to the reaction mechanism.
Original language | English |
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Pages (from-to) | 483-494 |
Number of pages | 12 |
Journal | Catalysis Today |
Volume | 54 |
Issue number | 4 |
DOIs | |
State | Published - Dec 17 1999 |
Externally published | Yes |
Event | Proceedings of the 1998 2nd World Congress on Environmental Catalysis 'Environmental Catalysis - Fundamental and Applied NOx Control Studies' - Miami, FL, United States Duration: Nov 15 1998 → Nov 20 1998 |
Funding
Financial support from the Director of the Chemistry Division, Basic Energy Sciences, U.S. Department of Energy, Grant DE-FGO2-87ER13654, is gratefully acknowledged.
Funders | Funder number |
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U.S. Department of Energy | DE-FGO2-87ER13654 |
Basic Energy Sciences |
Keywords
- Active catalyst deposits
- DeNO
- Fe/ZSM-5
- SCR of NO
- Transformation of N into N adsorption complexes