Low-temperature synthesis of LiBH4 by gas-solid reaction

Area of Science:

• Inorganic Chemistry
• Materials Science
• Hydrogen Storage

Background:

• Lithium borohydride (LiBH(4)) is a promising material for hydrogen storage.
• Current synthesis methods often involve harsh conditions or multiple steps.

Purpose of the Study:

• To develop a solvent-free, efficient synthesis of LiBH(4) from LiH.
• To investigate the reaction mechanism and identify rate-limiting steps.

Main Methods:

• Solvent-free synthesis of LiBH(4) from LiH in a borane atmosphere.
• Utilizing a LiBH(4)/ZnCl(2) mixture as the borane source via metathesis.
• Reaction conducted at 120°C and ambient pressures.

Main Results:

• Demonstrated solvent-free synthesis of LiBH(4) with a yield of approximately 74%.
• Confirmed bulk reaction upon borane absorption by LiH.
• Identified B-H bond formation as the rate-limiting step.

Conclusions:

• The use of diborane circumvents B-B bond dissociation barriers, enabling moderate synthesis conditions.
• This method offers an efficient route to LiBH(4) for potential hydrogen storage applications.