Kinetics of sodium borohydride hydrolysis catalyzed via carbon nanosheets supported Zr/Co

Porous sheet-like activated carbon was prepared in a fluidized bed using peanut shell as carbon precursor. Cobalt and zirconium were impregnated onto the carbon by impregnation-chemical reduction method to obtain carbon nanosheets supported Co and Zr/Co catalysts. The samples were characterized using field emission scanning electron microscopy, X-ray diffraction, H2-temperature-programmed reduction, and nitrogen adsorption measurements. It was found that the introduction of zirconium to the carbon-supported cobalt led to an intensified interaction between cobalt and the support. With the activation energy of 34.84 kJ mol−1 and maximum hydrogen generation rate of 1708 mL min−1 g−1, this novel carbon-supported Zr/Co catalyst exhibited superior catalytic activity for the hydrolysis of NaBH4 in alkaline medium. Furthermore, the effects of temperature, catalyst amount, and concentration of NaOH and NaBH4 on the hydrolysis process were systematically studied, and an overall kinetic rate equation was described as r = Ae−34840/(RT)[catalyst]1.53[NaOH]−0.54[NaBH4]0.43.

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► Peanut shells can be readily converted into porous carbon nanosheets in a fluid bed.
► Zr/Co/C catalyst has been obtained by loading Zr and Co on the carbon surface.
► Zr/Co/C exhibits good catalytic activity for NaBH4 hydrolysis in PEM fuel cells.
► A kinetic rate equation for Zr/Co/C catalyzed hydrolysis of NaBH4 is obtained.