METHOD FOR PREPARING COMPOSITIONS BASED ON OXIDES OF ZIRCONIUM AND CERIUM Russian patent published in 2019 - IPC C01G25/02 C01F17/00 B01J21/06 B01J23/10 B01D53/94 

FIELD: manufacturing technology.

SUBSTANCE: invention can be used in production of three-route catalysts for exhaust gases purification. Method of obtaining compositions based on zirconium and cerium oxides used in three-route catalysts involves preparing a solution containing nitrates of zirconium, cerium, lanthanum and another rare-earth element selected from yttrium and neodymium. Suspension is prepared by mixing said solution and basic compound. Concentration of metal oxides in solution containing nitrates of zirconium, cerium, lanthanum and other rare-earth element is at level from 20 to 30 g/dm³ in terms of final composition. Prior to precipitation, ammonium nitrate is added to solution to achieve concentration of 0.5 to 1 mol/dm^3. Suspension is prepared while stirring and maintaining the pH value at level of 8–10 due to controlled simultaneous dosing of the solution containing nitrates of zirconium, cerium, lanthanum and other rare-earth element, as well as ammonium nitrate and aqueous ammonia solution into the total reaction volume. Performing hydrothermal treatment with holding at temperature of 70–160 °C for 0.25–48 hours. Surfactants are added to the suspension, filtered, dried and calcined obtained residue at 500–1,000 °C.

EFFECT: invention increases specific surface of the product, reduces the amount of surfactant used, increases resistance of the composition to high temperatures.

1 cl, 1 tbl, 7 ex