The present invention is directed to an improved catalyst support and to the resultant catalyst suitable for treating exhaust products from internal combustion engines, especially diesel engines. The support of the present invention is a structure comprising alumina core particulate having high porosity and surface area, wherein the structure has from about 1 to about 8 weight percent silica in the form of cladding on the surface area of said alumina core. The resultant support has a sulfur tolerance efficiency (eta) of at least 1000 [mu]g/m2.