Kinetics of NaBH4 hydrolysis on carbon-supported ruthenium catalysts

In this work, different shapes (powder and spherical) of ruthenium-active carbon catalysts (Ru/C) were prepared by impregnation reduction method for hydrogen generation (HG) from the hydrolysis reaction of the alkaline NaBH4 solution. The effects of temperature, amount of catalysts, and concentration of NaOH and NaBH4 on the hydrolysis of NaBH4 solution were investigated with different shapes of Ru/C catalysts. The results show that the HG kinetics of NaBH4 solution with the powder Ru/C catalysts is completely different from that with the spherical Ru/C catalysts. The main reason is that both mass and heat transfer play important roles during the reaction with Ru/C catalysts. The HG overall kinetic rate equations for NaBH4 hydrolysis using the powder Ru/C catalysts and the spherical catalysts are described as r = A exp (-50740/RT) [catalyst](1.05) [NaOH](-0.13) [NaBH4](-0.25) and r = A exp (-52,120/RT) [catalyst](1.00) [NaOH](-0.21) [NaBH4](0.27) respectively. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.