Abstract
NO reduces HNO3 to HONO and surface nitrates to nitrites on a BaNa-Y zeolite, and it reacts with NO2 to form N2O 3. Data are also presented which show that adsorbed NO+ reacts with water to form HONO. In the presence of NH3 and H 2O these processes lead to the formation of ammonium nitrite, which efficiently decomposes near 100°C to N2 + H2O, effecting the catalytic reduction of NOx to N2. A criterion for this path is that the optimum yield of N2 is obtained with an equimolar mixture of NO + NO2. Since ammonium nitrate, which can also form on this catalyst, does not significantly decompose at 200°C, a typical temperature for diesel exhaust, the reduction of nitrate to nitrite serves to regenerate active sites on the BaNa-Y zeolite.
Original language | English |
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Pages (from-to) | 181-193 |
Number of pages | 13 |
Journal | Journal of Catalysis |
Volume | 231 |
Issue number | 1 |
DOIs | |
State | Published - Apr 1 2005 |
Externally published | Yes |
Funding
This work was supported by the EMSI program of the National Science Foundation and the U.S. Department of Energy, Office of Science (CHE-9810378) and by Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy, Grant No. DE-FG02-03ER15457 at the Northwestern University Istitute for Environmental Catalysis.
Funders | Funder number |
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Office of Basic Energy Sciences | |
National Science Foundation | |
U.S. Department of Energy | |
Office of Science | CHE-9810378 |
Chemical Sciences, Geosciences, and Biosciences Division |
Keywords
- Ammonia
- Ammonium nitrate
- FT-IR
- NO reduction mechanism
- Nitrate ions on zeolites
- Nitrate reduction on zeolites
- Nitrous acid