Method for sealing cells in extruded monoliths and devices resulting

Disclosed is a method for sealing selected cells in an extruded monolith at an end face of the monolith by providing an extruded monolith having a plurality of cells extending along a common direction and one or more end faces at which one or more of the cells are open, the open cells including some to be sealed and some to remain open, and by filling the open end of one of the cells to be sealed with a plug comprising a glass frit, such that an exterior portion the plug extends beyond the end of the cell, and such that the exterior portion of the plug also extends beyond the width of the cell; and by heating the extruded monolith together with the plug sufficiently to cause the glass frit to consolidate and flow sufficiently to seal the respective cell.