Honeycomb structure comprising an outer cement skin and a cement therefor

A method of making a honeycomb structure comprising:

• extruding a honeycomb body, the honeycomb body comprising a plurality of cells extending axially between first and second opposing end faces of the honeycomb body, the cells comprising intersecting porous walls;
• shaping the honeycomb body, thereby exposing portions of the porous walls around a periphery of the honeycomb body;
• coating the periphery of the shaped honeycomb body with a cement mixture, the cement mixture comprising a first glass powder filler material having a first particle size distribution with a D50 in a range from about 10 μm to about 50 μm, and a second glass powder filler material having a second particle size distribution with a D50 in a range from about 150 to about 300 μm, thereby forming a honeycomb structure;
• drying the cement mixture;
• and
• wherein an average coefficient of thermal expansion of the cement mixture from 600° C. on cooling to 23° C. is equal to or less than about 15×10−7/° C.