Formation of hydrogen cyanide over Cu/ZSM-5 catalyst used for the removal of nitrogen oxides from exhausts of lean-burn engines
- Swiss Federal Inst. of Technology, Zuerich (Switzerland)
Our experiments demonstrate the formation of harmful byproducts during the selective catalytic reduction of NO{sub x} over Cu/ZSM-5. The presence of water in the exhaust gas does not eliminate the hydrogen cyanide formation problem. This behavior together with the limited thermal stability renders this catalyst doubtful for the application in diesel exhaust systems. On the basis of the results of this and our previous studies, it seems advisable to reexamine the catalytic performance of other zeolite and oxide catalysts that have been proposed to be suitable for the removal of NO{sub x} under lean gas conditions. Avoidance of HCN formation adds another criterion for the suitability of future lean exhaust catalyst developments. Studies concerning the reaction mechanism are presently undertaken in our laboratory aiming at the design of catalysts that do not produce hazardous HCN. 26 refs., 4 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 121604
- Journal Information:
- Environmental Science and Technology, Vol. 29, Issue 10; Other Information: PBD: Oct 1995
- Country of Publication:
- United States
- Language:
- English
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