METHOD FOR PREPARING AUTOMOBILE THREE-WAY CATALYST Russian patent published in 2021 - IPC B01J37/25 B01J37/08 B01J23/10 B01J23/44 B01J23/42 B01J23/40 B01J23/02 B01J21/04 B01D53/94 

FIELD: vehicles.

SUBSTANCE: invention relates to a method for preparing an automobile three-way catalyst, including the stages of preparing suspensions for an inner and outer catalytically active layer with a content of precious metals from 5 to 100 g/ft³ in each suspension, obtaining a single-layer catalytic brick by applying the suspension for the inner layer onto a substrate, drying the single-layer catalytic brick at 150°C for 2 hours and firing at 450 to 550°C for 4 hours, obtaining a two-layer catalytic brick by applying the suspension for the outer layer onto the single-layer catalytic brick, drying the two-layer catalytic brick at 150°C 2 hours and firing at 450 to 550° for 4 hours, wherein a ground suspension of aluminum oxide with a diameter value at a percentage by weight of particles of a given size less than 90% of the total content (d90) of less than 9.5 mcm is used as a suspension for the inner layer, precious metals are added into the suspension for the inner layer by introducing a solution of palladium nitrate and rhodium nitrate, a modifier is added to the suspension for the inner layer by introducing barium nitrate or acetate, the mass fraction of barium in the catalytically active coating relative to barium oxide is from 1.5 to 5% wt.%, a ground suspension of a composition based on cerium and zirconium oxide with a percentage by weight of particles of a given size less than 90% of the total content (d90) of less than 9.5 mcm is used as a suspension for the outer layer, precious metals are added to the suspension for the outer layer by introducing a solution of palladium nitrate, a modifier is added to the suspension for the outer layer by introducing lanthanum nitrate, the mass fraction of lanthanum in the catalytically active coating relative to lanthanum oxide is from 1.5 to 5% wt.

EFFECT: increasing the thermal stability of the composition based on cerium oxide and zirconium, increasing the catalytic activity in conversion reactions of carbon monoxide, hydrocarbons and nitrogen oxides, as well as in increasing the oxygen capacity.

1 cl, 1 dwg, 7 ex