Hydrogen generation from hydrolysis of sodium borohydride using sulfonated porous carbon as reagent/catalyst

Abstract

The hydrolysis of sodium borohydride as a source of hydrogen gas is studied at different mole ratios of H+ to NaBH4. The sulfonated porous carbon (SPC) is used as a source of hydrogen ion and catalyst. It is found that the sulfonated porous carbon exhibits high activity for the hydrolysis of NaBH4 to generate hydrogen gas at room temperature in comparison to Amberlyst-15 and Nafion-NR50. The kinetic rate constant of hydrolysis reaction is calculated by measurement of the evolved hydrogen gas as a function of time. The kinetic rate constant of NaBH4 hydrolysis is approximately increased 7.6 times at presence of SPC as a solid acid/catalyst versus blank hydrolysis reaction. The activation energy of sodium borohydride hydrolysis is obtained 1.24 KJmol-1.The kinetic rate constant (kapp, s-1) of hydrogen generation reaction increased from 0.023 to 0.626 with increasing of H+(SPC)/NaBH4 from 0.25 to 1.50. The SPC activity with mole ratio of H+/NaBH4=1 show an efficiency of 91% at time 25s.