Sodium borohydride and propylene glycol, an effective combination for the generation of 2.3 wt% of hydrogen

Abstract

Sodium borohydride NaBH4 (SB) readily and completely reacts with four equivalents of propylene glycol HOCH2CH(OH)CH3 (PG), resulting in the liberation of four equivalents of H2 at temperatures starting from 25 °C. Alcoholysis (or glycolysis) takes place. The system SB-4PG is then an attractive H2 generator thanks to an effective gravimetric hydrogen storage capacity of 2.3 wt%. It offers several other advantages: there is no need of catalyst; there is no precipitation of by-product; PG is among the safest alcohols (much safer than e.g. methanol). The potential of SB-4PG as H2 generator is thus illustrated and discussed herein.