| 摘要 |
PROBLEM TO BE SOLVED: To provide catalyzed soot filters for diesel engine exhaust emissions systems and methods for their manufacture and use.SOLUTION: A honeycomb filter of a wall flow monolith includes microcracks having an average width less than 0.4 μm, and pores having a mean pore size in the range of 10 to 25 μm. A washcoat is disposed within walls of the wall flow monolith. The washcoat includes a catalyst comprising support particles and at least one precious metal, where at least 90% of the support particles have particle sizes greater than the average size of the microcracks and at least 90% of the support particles have particle sizes less than the mean size of the pores of the wall flow monolith. The wall flow monolith comprises aluminum titanate having a porosity in the range of 40 to 70%. The soot filter exhibits a coefficient of thermal expansion less than 25×10/K when measured at 1000°C. |
