Cerium chloride heptahydrate

Cerium chloride heptahydrate (CAS 18618-55-8), also designated cerium(III) chloride heptahydrate or cerous chloride heptahydrate, is the most widely handled water-soluble form of this rare earth element.

Where is Cerium chloride heptahydrate used?

• Pharmaceutical and fine-chemical synthesis: Lewis acid promoter in Luche reductions and co-reagent in Grignard-type additions, selectively activating carbonyl substrates to improve chemoselectivity
• Intermediate in the preparation of other cerium salts and organometallic cerium reagents
• Oil, gas and energy: catalyst precursor and research-grade corrosion inhibitor candidate for water-treatment circuits, where cerium(III) ions modify oxide surface layers and reduce electrochemical corrosion rates
• Home care and industrial cleaning: research into hard-surface treatments and functional coatings, where controlled deposition of rare earth species alters substrate wettability or enhances protective film formation
• The crystalline heptahydrate dissolves readily in aqueous and polar media, making it a starting point for downstream cerium chemistry.

Good to know: The anhydrous form (CAS 7790-86-5) is a related material for moisture-sensitive processing. Covered by the REACH registration of cerium trichloride (EC 232-227-8); carries a Warning signal word under CLP classification, and the current Safety Data Sheet should be consulted before use.

Commercial specifications

• TREO ≥ 99 % up to CeO₂/TREO ≥ 99.99 %, quoted on a rare earth oxide basis
• Heptahydrate TREO content approximately 45 %
• Purity tiers confirmed on a batch certificate basis; buyers should verify against process requirements
• Packaging: 1–5 kg units for laboratory and high-purity applications, 25 kg drums for process quantities; solution forms available for direct liquid dosing