PERFORMANCE OF BI-AND TRI-METALLIC MORDENITE CATALYSTS FOR THE LEAN SCR OF NOx BY METHANE

摘要

The lean NOx reduction by methane in the presence of 10-15% water vapor was studied onrnseveral bi- and tri-metallic powder catalysts containing two or three of the following species: Co, Pd,rnCe, and Pt supported on HMOR. A cooperative effect in the Pd-Co, Pd-Ce, Pd-Ce-Co and Pd-rnPt-Ce systems was found for CH_4-SCR under wet conditions. Pd-Ce/HMOR and Pd-Ce/Co-rnHMOR catalysts were more tolerant to the coexistence of H_2O and SO_2 in the gas feed thanrnPd/Co-HMOR. Co, Pd and Ce species were impregnated on ceramic monoliths washcoated withrnmordenite. The quantitative results of NOx reduction were different for the monolithic and powderedrncatalysts. However, a similar trend in the CH_4-SCR activity of both catalyst types was observed.