초록 ▼

An extrudate catalyst suitable for auto emission control is made from a solid, transitional alumina. It has a partially hollow interior and one or more platinum group metals deposited on the extrudate. The cylindrical extrudate has internal reinforcing vanes or ribs extending from the inner wall to

An extrudate catalyst suitable for auto emission control is made from a solid, transitional alumina. It has a partially hollow interior and one or more platinum group metals deposited on the extrudate. The cylindrical extrudate has internal reinforcing vanes or ribs extending from the inner wall to the center of the extrudate particle. This configuration permits the catalyst to have the large geometric surface area per reactor volume yet, because of the openings inside the extrudate, the catalyst particles do not exhibit a large pressure drop when packed in a deep bed. These catalysts provide greater hydrocarbon and carbon monoxide conversions than do similar size spherical particles and they have improved light-off characteristics.

대표청구항 ▼

A catalyst suitable for auto emission control comprising a solid, transitional alumina extrudate support structure having a cylindrical, hollow annular configuration with internal reinforcing vanes, a nitrogen surface area of at least 50 m2/g; a diameter of up to about 6.5 mm; an aspect ratio of the

A catalyst suitable for auto emission control comprising a solid, transitional alumina extrudate support structure having a cylindrical, hollow annular configuration with internal reinforcing vanes, a nitrogen surface area of at least 50 m2/g; a diameter of up to about 6.5 mm; an aspect ratio of the length to the diameter of from about 1 to 5; a geometric surface area of at least 25% greater than a hollow tube of the same inside and outside diameter; a porosity of at least 0.3 cm3/g; a surface area per reactor volume of at least 5 cm2/cm3 and a catalytically-effective amount of one or more platinum group metals deposited directly on the support structure without having any washcoat present.