| 摘要 |
<p>PURPOSE:To enhance not only collection efficiency but also regeneration capacity by suppressing the formation of sulfate, by supporting a base metal by a whole of a filter base material and allowing the upstream side part of said base material to support one or more of a platinum group metal. CONSTITUTION:One or more of a base metal having sulfate suppressing effect selected from Cu, La, Mg, Mn and Zn is supported by a whole of a base material such as a ceramic foam filter or a ceramic honeycomb filter. Further, one or more of a platinum group metal is supported by the part of the filter base material of 10-50% from the upstream side end surface thereof. By this method, the ignitability of the platinum group metal and the combustion propagating property of the base metal can be effectively utilized and the reaction between the platinum group metal and sulfur dioxide is suppressed to prevent the lowering in collection efficiency due to the formation of sulfate.</p> |
