abstract |
Ceric oxide particulates having a specific surface of at least 190 m2/g, measured after calcination at a temperature of from 350 degrees to 450 degrees C., and a specific surface of at least 15 m2/g after calcination at 800 degrees C., are prepared by (a) suspending, in an aqueous solution of a decomposable base, a ceric hydroxide of the formula (I): Ce(M)x(OH)y(NO3)z (I) wherein M is an alkali metal or a quaternary ammonium radical; x is a number ranging from 0.01 to 0.2; y is such that y=4-z+x; and z is a number ranging from 0.4 to 0.7; (b) heating the resulting suspension in a confined reaction zone to a temperature and pressure respectively lower than its critical temperature and pressure; (c) cooling such reaction medium and permitting it to return to atmospheric pressure; (d) separating the ceric hydroxide thus treated; and (e) calcining the separated ceric hydroxide. |