Nanocrystal-sized cerium-zirconium-aluminum oxide material and method of making the same

Abstract

A nanocrystal-sized cerium-zirconium-aluminum mixed oxide material includes at least 20% by mass zirconium oxide; between 5% to 55% by mass cerium oxide; between 5% to 60% by mass aluminum oxide; and a total of 25% or less by mass of at least one oxide of a rare earth metal selected from the group of lanthanum, neodymium, praseodymium, or yttrium. The nanocrystal-sized cerium-zirconium-aluminum mixed oxide exhibits hierarchically ordered aggregates having a dso particle size less than 1.5 μm, and retains at least 80% of surface area and pore volume after ageing at temperature higher than 1000° C. for at least 6 hours. The nanocrystal-sized cerium-zirconium-aluminum mixed oxide material is prepared using a co-precipitation method followed by milling the dried and calcined oxide material. The nanocrystal-sized cerium-zirconium-aluminum mixed oxide material forms a particulate filter that may be used in an exhaust system arising from a gas or diesel engine.

Dependencies are inferred from the claim text.