Producing Alkali Metal Hydrides from Hydroxides.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Chemical Engineering

Background:

• Alkali metal hydrides are crucial chemical intermediates.
• Existing production methods can be complex and costly.
• There is a need for efficient and scalable hydride synthesis.

Purpose of the Study:

• To present a novel, cost-effective method for producing alkali metal hydrides (NaH, KH, RbH, CsH) from their corresponding metal hydroxides.
• To investigate various metallic reducing agents for sodium hydride (NaH) production from sodium hydroxide (NaOH).
• To explore the potential of this NaH production method for sodium borohydride (NaBH4) applications and hydrogen export.

Main Methods:

• Reactions conducted in an autoclave reactor under controlled conditions (250 °C, 14 bar H2 pressure) using paraffin oil.
• Investigated metallic reducing agents including Mg, Al, Si, CaH2, Cr, Mn, and Sr for NaH synthesis.
• Implemented a two-step process involving metal formation followed by hydrogenation to simplify purification.

Main Results:

• Successfully produced various alkali metal hydrides from their respective hydroxides.
• Identified effective metallic reducing agents for NaH production.
• Demonstrated that a two-step process enhances separation and purification of metal hydrides.

Conclusions:

• The presented method offers a viable, cost-effective alternative for alkali metal hydride production.
• The process is adaptable for producing sodium hydride, with implications for sodium borohydride synthesis and hydrogen storage.
• This research contributes to advancing efficient chemical synthesis and hydrogen economy technologies.