| 摘要 |
A compsn. based on mixed oxides of Zr and Ce is prepd. by (i) mixing, in stoichiometric proportions corresponding to those of the desired final compsn., a Zr sol and a Ce sol, the ratio r between the mean dia. r1 of the particles constituting the Zr sol and the mean dia. r2 of the particles constituting the Ce sol being at least 5, (ii) adding a base to the resulting mixt., (iii) recovering the ppte. formed and (iv) calcining the ppte. The compsn. prepd in the main claim is also claimed. Pref. prod. comprises (expressed as oxides) 51-99 wt. % Zr and 1-49 wt. % Ce and, if present, 0.1-20 wt. %, esp. 1-10 wt. % of the dopant element. The dopant element is pref. in solid soln. in the Zr oxide and/or the Ce oxide. The prod. has a specific surface of at least 10 m<2>/g, pref. at least 20 m<2>/g, esp. at least 30 m<2>/g and partic. 40 m<2>/g. |
