Lanthanum(III) Nitrate Hexahydrate
Properties
| State | Solid (hygroscopic) |
| Color | Colorless to pale yellow |
| Solubility | Very soluble in water (2000 g/L); soluble in alcohols and acetone |
| Melting Point | 40 °C (hexahydrate decomposes) |
About Lanthanum(III) Nitrate Hexahydrate
Lanthanum(III) nitrate hexahydrate is the workhorse precursor for almost any solution-phase preparation of a lanthanum-containing material — about 2000 g/L water solubility (one of the highest of any La compound), no oxychloride formation problem on dehydration the way LaCl3 has, and it decomposes cleanly to La2O3 around 500°C, making it ideal for sol-gel and impregnation chemistry. In the crystal each La(III) sits in a 10-coordinate capped square antiprism: three bidentate nitrate groups contribute six oxygens, plus four water molecules. That high coordination number is typical of early lanthanides where the ionic radius (1.172 Å for 9-coordinate La(III)) leaves room for crowded inner spheres. The two big industrial uses are catalyst preparation and pharmaceutical chemistry. La-exchanged zeolite Y is the dominant catalyst in fluid catalytic cracking — La3+ ions stabilize the zeolite framework against the steam and 700°C of the FCC regenerator — and the La salt of choice for the ion-exchange step is the nitrate. On the pharma side, La(NO3)3 is converted (via carbonate precipitation) to lanthanum carbonate, the active ingredient in Fosrenol — the FDA-approved (2004) phosphate binder prescribed for hyperphosphatemia in dialysis patients. La3+ binds dietary phosphate in the gut as insoluble LaPO4, preventing absorption and the vascular calcification that wrecks long-term dialysis outcomes.
Where you'll encounter it
If you've ever pumped gas at a US refinery whose FCC unit runs La-zeolite catalyst, or filled a Fosrenol prescription for a family member on dialysis, the supply chain traces back through La(NO3)3·6H2O. Refineries in Texas, Louisiana, and across the Gulf Coast process about 14 million barrels of crude per day through fluid catalytic cracking units, and every one of those FCC units burns through La-stabilized zeolite Y catalyst at roughly 1-2 tonnes per day — the lanthanum charge into that catalyst originates as La(NO3)3·6H2O dissolved into the ion-exchange step. Dialysis pharmacies dispense Fosrenol chewable tablets to patients with end-stage renal disease who can't excrete dietary phosphate; the lanthanum carbonate active ingredient is precipitated from this exact nitrate solution. Sol-gel chemists also reach for it as the cleanest precursor for nano-La2O3 catalyst supports.
Common Uses
- Wet-impregnation precursor for La-zeolite Y in petroleum FCC catalysts
- Lanthanum carbonate feedstock for Fosrenol (oral phosphate binder)
- Sol-gel precursor for LaMnO3 and LaCrO3 SOFC cathode powders
- Calcination precursor for nano-La2O3 catalyst supports
- Selective phosphate and fluoride precipitation in analytical chemistry
- Nitrate-based precursor for thin-film deposition of La-doped oxides
- Dopant source in glass batches for high-refractive-index optical lenses
Safety Information
GHS classifications: H272 (oxidizing solid Cat 3), H315 (skin irritation Cat 2), H319 (eye irritation Cat 2A). The nitrate counter-ion is the dominant hazard — fire risk when contaminated with combustibles like wood dust, paper, or oils. Hot solutions evolve NOx vapors. OSHA has no specific PEL for lanthanum compounds; ACGIH defers to nuisance-dust limits of 10 mg/m3 total / 5 mg/m3 respirable. Store separately from organic chemicals, reducing agents, and acids. Spills clean up dry — never sweep into trash with combustible materials.
This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals.