The Production of NaBH₄ from Its Elements by Mechano-chemical Reaction and Usage in Hydrogen Recycle

Abstract

In this study, sodium borohydride (NaBH₄) is synthesized from Na and MgH₂ in the presence of B₂O₃ that behaves as a stickiness inhibitor and boron source. All experiments are performed under argon atmosphere via ball milling, without applying high temperature or pressure. An optimum synthesized parameter is searched with reaction time and stochiometric ratio. Mechano-chemical reactor working time is varied from 100 to 1,100 min, while stoichiometry of B₂O₃/Na ranges over 0.6–1.4, and MgH₂ is used 30% in excess. FT-IR and XRD instruments are utilized to analyze the products. Additionally, hydrogen contents of the untreated products are measured with the inverse burette technique. Consequently, results show that long reaction times favor the yield. Moreover, equalizing the amounts of B₂O₃ and MgH₂ can raise NaBH₄ yield to 25% or more.

Keywords:

• dehydrogenation
• hydrogen carrier
• hydrogen storage
• NaBH₄
• solid phase reaction