| 摘要 |
<p>Composition (A) comprising zirconium oxide, cerium oxide, lanthanum oxide and oxide of another rare earth e.g. yttrium, samarium and gadolinium, presents a specific surface of >=40 m 2>/g after calcination for 4 hours at 1000[deg]C, a specific surface of >=15 m 2>/g after calcination for 10 hours at 1150[deg]C, a specific surface of >=7 m 2>/g after calcination for 10 hours at 1200[deg]C and a content of lanthanum oxide and oxide of other rare earth metals at >=15%. Independent claims are included for: (1) preparation of (A) comprising preparing a mixture in a liquid medium containing zirconium, cerium, lanthanum and other rare earth compounds, contacting the mixture with basic compound to obtain a precipitate, heating the precipitate in a liquid medium, adding additives such as to the obtained precipitate anionic surfactants, non-ionic surfactants, polyethyleneglycols, carboxylic acids and their salts or ethoxylate type surfactant of fatty carboxymethyl alcohols, washing the obtained precipitate and calcining the obtained precipitate; (2) a catalytic system, comprising (A); and (3) treatment of exhaust gases from internal combustion engines, using the catalytic system.</p> |
