Substrate used for exhaust gas purification and method of fabrication thereof

A substrate used for purifying the exhaust gas, comprising:

• a first end;
• a second end;
• a plurality of partition walls extending between the first end and the second end;
• and
• a plurality of passages defined by the plurality of the partition walls;
• wherein the ends of a plurality of the partition walls at the first end of the substrate defining one of each two adjacent passages are collected toward the center of a corresponding passage and connected with each other, the end surface of the partition wall ends at the first end of the substrate being depressed toward the center of the end surface;
• and
• wherein the ends of a plurality of the partition walls at the second end of the substrate defining the remaining one of the two adjacent passages are collected toward the center of the corresponding passage and connected with each other, the end surface of the partition walls at the second end of the substrate being depressed toward the center of the end surface.