FIELD: chemistry.
SUBSTANCE: invention relates to perovskite-type oxide compositions on an aluminium oxide carrier used in catalytic systems for controlling exhaust gas emissions. Disclosed is a method of producing a perovskite-type oxide composition on an aluminium oxide support, involving the following steps: i) obtaining doped aluminium oxide, wherein doped aluminium oxide includes: aluminium oxide and rare-earth oxide, or aluminium oxide and alkali-earth oxide, or aluminium oxide and mixture of rare-earth oxide and alkali-earth oxide, wherein doped aluminium oxide is obtained by a method comprising at least the following steps: A) preparing a suspension of boehmite, B) preparing an aqueous salt solution, wherein the aqueous salt solution includes a rare-earth element salt, or an alkali-earth element salt, or a mixture of a rare-earth element salt and an alkali-earth element salt; C) combining the boehmite suspension with an aqueous salt solution to form a mixture of boehmite with a salt; D) drying the mixture of boehmite and salt to obtain a dried mixture of boehmite and salt; and E) calcining the dried mixture of boehmite with a salt to form a doped aluminium oxide; ii) impregnating doped aluminium oxide with an aqueous impregnation solution, wherein the aqueous impregnation solution contains one or a mixture of water-soluble salts of rare-earth elements, water-soluble salts of alkali-earth elements, water-soluble salts of alkaline elements, water-soluble salts of Pb2+, water-soluble salts of Bi3+ and water-soluble salts of transition metals to form impregnated doped aluminium oxide; and iii) calcining the impregnated doped aluminium oxide, wherein at least 50 wt.% of any rare-earth oxide, alkali-earth oxide or mixture thereof, which are present in the perovskite-type oxide composition on an alumina support, are added to the suspension of boehmite in form of a rare-earth salt, an alkali-earth salt or a mixture thereof at step i) C), to form a rare-earth oxide, an alkali-earth oxide or a mixture thereof from a salt by calcination in step i) E). Also disclosed is a perovskite-type oxide composition on an aluminium oxide support obtained using the disclosed method.
EFFECT: obtained composition is homogeneous, has a perovskite structure and has improved specific surface area and pore volume.
8 cl, 5 dwg, 2 tbl, 3 ex
