| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a honeycomb structure wherein the purification rate of NOx can be improved in a wide temperature range, in a SCR (selective catalytic reduction) system. <P>SOLUTION: The honeycomb structure 10 includes honeycomb units 11 each of which contains zeolite and an inorganic binder and in each of which a plurality of through-holes 12 are arranged side by side in the longitudinal direction while being divided by partition walls 15. The zeolite to be used contains the first zeolite the ion of which is exchanged with one or more elements selected from the group consisting of Cu, Mn, Ag and V and the second zeolite the ion of which is exchanged with one or more elements selected from the group consisting of Fe, Ti and Co. The ratio of the weight of the first zeolite to the total weight of the first zeolite and the second zeolite is made larger in the center of the partition wall and smaller on the surface thereof. However, the ratio of the weight of the second zeolite to the total weight of the first zeolite and the second zeolite is made larger on the surface of the partition wall and smaller in the center thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT |
