General Description Cerium(III) chloride heptahydrate is a mild Lewis acid. It participates in the allylation of aldehydes. Cerium(III) chloride heptahydrate in combination with sodium iodide supported on silica gel efficiently promotes Michael-type addition. Cerium(III) chloride heptahydrate in the presence of sodium iodide acts as an efficient catalyst for the Michael addition of 1,3-dicarbonyl compounds to α,β-unsaturated ketones and α,β-unsaturated aldehydes. Application Cerium(III) chloride heptahydrate was used for the preparation of undoped ceria nanoparticles. It may be used in the preparation of 2-indolyl-1-nitroalkane derivatives and CeO 2 -supported Co catalysts.