Determination of cerium(III) and cerium(IV) in nanodisperse ceria by chemical methods

Percentages of different valence cerium species have been determined in powdery samples, redispersible compositions, and aqueous sols of nanodisperse ceria prepared from cerium(IV) and cerium(III) salts by various methods with or without organic stabilizers. Cerium(III) is shown to be virtually absent in nearly all of the CeO2 samples studied. Organic stabilizers are shown to be capable of reducing cerium(IV) in aqueous CeO2 sols.