Lean NOx reduction CuZSM5 catalysts: Evaluation of performance at the spark ignition engine exhaust
✍ Scribed by P. Ciambelli; P. Corbo; M. Gambino; G. Minelli; G. Moretti; P. Porta
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 513 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0920-5861
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✦ Synopsis
CuZSM5 catalysts, prepared by ion exchange of HZSM5 (Si/A1 = 80), enable selective lean NOx reduction at the spark ignition engine exhaust. All catalysts, even if exchanged to very high copper loading (556% apparent exchange level) give no evidence for segregated copper oxide phases. In the presence of water they are easily reduced in vacuum at 550°C and are stable to redox cycles (02, vacuum) treatments. Increasing Cu content to about 200% apparent exchange level results in increasing NOx, CO and HC conversions. From 200 to 550% exchange CuZSM5 catalysts give similar performances. Preliminary investigation shows that after catalytic tests there is evidence for CuO formation only in the copper-richest catalysts.