Patent ID: 8876926

Claim:
A process for preparing a cerium oxide suspension comprising the following steps: (a) providing a solution of a cerium III salt which also comprises a colloidal dispersion of cerium IV, wherein cerium IV is cerium oxide and/or cerium oxide hydrate; (b) contacting this solution with a base, under an inert atmosphere, whereby a precipitate is obtained; (c) subjecting the medium obtained in the preceding step to a thermal treatment under an inert atmosphere, at least one of steps (a), (b) or (c) being carried out in the presence of nitrate ions; and (d) acidifying and washing the medium thus obtained carried out successively but in any order, whereby the suspension is obtained, wherein the suspension comprises monodisperse cerium oxide particles in a liquid phase, the particles (secondary particles) of which have an average size of at most 200 nm, such secondary particles comprising primary particles whose average size measured by TEM is at most 150 nm with a standard deviation of at most 30% of the value of said average size, and for which the ratio of the average size measured by TEM to the average size measured by BET is at least 1.5.