Influence of temperature and alkalinity on the hydrolysis rate of borohydride ions in aqueous solution

Production of formic acid from CO2 reduction by means of potassium borohydride at ambient conditions

“…The overall reaction for the reduction of CO 2 with BH 4 À The borane formed after hydrogen evolution is then quickly hydrolyzed to the hydroxyborohydride intermediate seen as a 1:1:1:1 quartet at 2.3 ppm in the 1 H NMR spectra and a 1:3:3:1 quartet at À13 ppm in the 11 B spectrum ( 1 J H-11B ¼ 80.6 Hz) (Andrieux et al, 2011;Churikov et al, 2012). Reports by Ruman et al (2007) and Reed and Jolly (1977) indicate that this ordinarily short lived species may in fact be more reactive than BH 4 À itself, and we therefore believe that this is the species responsible for the reduction of dissolved CO 2 .…”

Separate Determination of Borohydride, Borate, Hydroxide, and Carbonate in the Borohydride Fuel Cell by Acid-Base and Iodometric Potentiometric Titration

“…Borohydride hydrolysis reaction (6) takes place in aqueous alkaline solutions even at high pH but its rate is extremely low [21]. Table 1 comprises approximate rates of BH 4 − decomposition due to hydrolysis at 25 ∘ C. One can see that the hydrolysis of BH 4 − slowly proceeds at pH ≈ 11-13 in the solutions at acid-base titration, but this hydrolysis is part of the analytical procedure.…”

“…Hydrolysis is sharply accelerated at pH ≈ 7-9 and the borate ions formed are further bound in reaction (7). No complex mechanism of the protolysis of BH 4 − ions [8,21,34] is reflected on the titration curve pH versus .…”

“…The fuel of DBFCs is a multiple mixture whose specific characteristics directly depend on the ratio of its components BH 4 − /OH − /H 2 O [19][20][21][22][23][24]. It can be an aqueous solution of NaOH and NaBH 4 in the initial state and an aqueous solution of NaOH, NaBH 4 , and NaBO 2 in the discharged (partially or fully) state.…”

Stabilising mannose using sodium dithionite at alkaline conditions

“…Sodium borohydride has the advantage of being a stronger reducing agent than sodium dithionite. Additionally, unlike dithionite, borohydride is stabilised at pH ≥ 13 (Churikov et al 2012). However, sodium borohydride risks introducing the non-process element boron into the chemical recovery system and has been found to have reproductive toxicity (Weir and Fisher 1972), causing it to be labelled as a carcinogenic, mutagenic and reprotoxic (CMR) substance.…”