US Patent 7141089 Magnesium aluminum silicate structures for DPF applications

A ceramic filter for trapping and combusting diesel exhaust particulates composed of an end-plugged cordierite honeycomb structure exhibiting a pore size distribution as determined by mercury porosimetry in which the quantity d50/(d50+d90) as related to pore size distribution is less than 0.70, a soot loaded permeability factor Sf, as defined by the equation [d50/(d50+d90)]/[% porosity/100], of less than 1.55, and, a coefficient of thermal expansion (25–800° C.) of no greater than 17×10−7/° C. The ceramic filter further exhibits a median pore diameter, d50, of at least 4 micrometers and up to 40 micrometers. A method of making the filter is provided.