Calcium Tetrahydroaluminate

Calcium tetrahydroaluminate is a compound with the chemical formula Ca(AlH4)2. It is also known as calcium alanate or CaAlH5. The compound consists of calcium cations (Ca2+) and tetrahydroaluminate anions (AlH4-), which are coordinated in a lattice structure.

Calcium tetrahydroaluminate is a white, crystalline powder that is stable at room temperature and pressure. It is often used as a hydrogen storage material because it has a high gravimetric and volumetric hydrogen density, making it a promising candidate for use in fuel cells and other hydrogen-based technologies.

The compound can be synthesized by reacting calcium hydride (CaH2) with aluminum hydride (AlH3) in a solvent such as diethyl ether or tetrahydrofuran (THF). The reaction produces calcium tetrahydroaluminate and hydrogen gas (H2).

CaH2 + 2 AlH3 → Ca(AlH4)2 + H2

Calcium tetrahydroaluminate has a melting point of 150-152 °C and a boiling point of 200-250 °C. It decomposes at temperatures above 300 °C to release hydrogen gas and form calcium aluminum oxide (CaAl2O4).

Ca(AlH4)2 → 2 AlH3 + CaAl2O4 + 3 H2

Overall, calcium tetrahydroaluminate is a versatile compound with potential applications in hydrogen storage and other areas of materials science.