초록 ▼

This invention relates to a catalytic composite for treating an exhaust gas comprising a support which is a refractory inorganic oxide having dispersed thereon lanthanum, at least one other rare earth component and at least one noble metal component selected from the group consisting of platinum, pa

This invention relates to a catalytic composite for treating an exhaust gas comprising a support which is a refractory inorganic oxide having dispersed thereon lanthanum, at least one other rare earth component and at least one noble metal component selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium. An essential feature of said catalytic composite is that the lanthanum be present as crystalline particles of lanthanum oxide which have an average crystallite size of less than about 25 Angstroms. The support may be selected from the group consisting of alumina, silica, titania, zirconia, aluminosilicates and mixtures thereof with alumina being preferred. This invention also relates to a method of manufacturing said catalytic composite. In particular, an important feature of said method of manufacturing is the dispersion of lanthanum oxide onto said refractory inorganic oxide support.

대표청구항 ▼

A catalytic composite for treating an exhaust gas comprising a support which is a refractory inorganic oxide selected from the group consisting of alumina, silica, titania, zirconia, alumino-silicates and mixtures thereof, having dispersed thereon lanthanum oxide, the lanthanum oxide being dispersed

A catalytic composite for treating an exhaust gas comprising a support which is a refractory inorganic oxide selected from the group consisting of alumina, silica, titania, zirconia, alumino-silicates and mixtures thereof, having dispersed thereon lanthanum oxide, the lanthanum oxide being dispersed on said support by the method of commingling a solution of a lanthanum salt with a hydrosol of the metal precursor of said support, forming particles from said lanthanum containing hydrosol, calcining said particles to form a particulate support containing lanthanum oxide, having an average crystallite size of less than 25 Angstroms, at least one other rare earth oxide and at least one noble metal component selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium.