Sodium borohydride is one of the most well studied clean hydrogen sources owing to its high theoretical hydrogen storage capacity (10.8 wt%). Compared with other chemical hydrides, this inexpensive material is easy to handle because of its stability under inert and anhydrous conditions. Liberation of hydrogen gas is achieved via hydrolysis:
NaBH4 + 4H2O → NaB(OH)4 + 4H2
In hydrolysis, NaBH4 is typically dissolved in an alkaline solution, often sodium hydroxide (NaOH), which is then sent to a catalytic bed reactor to induce hydrogen release. A typical solution consists of 20% (wt) NaBH4, 10% (wt) NaOH, 70% (wt) water achieving gravimetric and volumetric hydrogen storage capacities of 4.2% (wt) and 42.3 kg/m3, respectively. The concentration of NaBH4 must be kept relatively low so that the precipitation of the products of hydrolysis, hydrated borates, can be avoided to prevent the poisoning of catalysts via the blocking of active sites. Catalysts for the hydrolysis of NaBH4 are most based on cobalt (Co), mainly due to their relatively low cost; catalysts based on Ru are generally more active, but also more expensive [1].
VENPURE™ sodium borohydride is available in the Strem Catalog in several modifications:
11-1117 VENPURE™ AF CAPLETS (sodium borohydride), min. 99%
11-1119 VENPURE™ SF GRANULE (sodium borohydride), min. 98.5%
93-1118 VENPURE™ SF POWDER (sodium borohydride), min. 98.5%
11-1120 VENPURE™ AF GRANULE (sodium borohydride), min. 99%
11-1121 VENPURE™ SOLUTION (sodium borohydride 12%; sodium hydroxide 40%)
There are plenty of comprehensive reviews on sodium borohydride where hydrogen storage and generation from NaBH4 is broadly discussed [e.g., 2-12].
References:
Featured Products
11-1117 VENPURE™ AF CAPLETS (sodium borohydride), min. 99%
11-1119 VENPURE™ SF GRANULE (sodium borohydride), min. 98.5%
93-1118 VENPURE™ SF POWDER (sodium borohydride), min. 98.5%
11-1120 VENPURE™ AF GRANULE (sodium borohydride), min. 99%
11-1121 VENPURE™ SOLUTION (sodium borohydride 12%; sodium hydroxide 40%)
11-1122 VENPURE™ 930 Solution (sodium borohydride 9%; sodium hydroxide 30%) [Coming Soon!]
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