Abstract
NO<inf>x</inf> conversion to N<inf>2</inf> was investigated by a plasma/catalyst system in rich oxygen similar to a lean-burn engine exhaust. Catalytic activity was enhanced by the assistance of plasma, and the plasma/catalyst system showed higher NO<inf>x</inf> conversion over a wider temperature window than did catalyst alone. The plasma/catalyst (Ag/Al<inf>2</inf>O<inf>3</inf>) system showed a remarkable improvement in NO<inf>x</inf> conversion in the lower temperature range under 400 °C. The NO<inf>x</inf> conversion of plasma/catalyst (Ag/Al<inf>2</inf>O<inf>3</inf>) was 40%-50%, and its selectivity to N<inf>2</inf> was over 96% under the conditions that the hydrocarbon (C1 base) to NO<inf>x</inf> ratio was about 3 and 10% O<inf>2</inf> existed over the temperature range of 300-500 °C. Ag/Al<inf>2</inf>O<inf>3</inf> showed a better performance than Al<inf>2</inf>O<inf>3</inf> when assisted by plasma. Helium was used as a balance gas to measure N<inf>2</inf> formation by gas chromatography, and NO<inf>x</inf> conversion was measured by a chemiluminescence NO<inf>x</inf> analyzer in N<inf>2</inf> balance as well as He balance. The result in N<inf>2</inf> balance gas was compared with the result in helium balance gas at the 300 °C where the largest enhancement by plasma was observed. The NO<inf>x</inf> conversion in N<inf>2</inf> balance gas was similar to that in helium balance gas, which verified that the plasma effect obtained in helium balance gas is consistent with that of N<inf>2</inf> balance gas, which is the largest component of the real exhaust gas.
Original language | English |
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Pages (from-to) | 1227-1232 |
Number of pages | 6 |
Journal | Proceedings of the Combustion Institute |
Volume | 28 |
Issue number | 1 |
Publication status | Published - 2000 |
Externally published | Yes |
ASJC Scopus subject areas
- Mechanical Engineering
- General Chemical Engineering
- Physical and Theoretical Chemistry