STUDIES ON CATALYTIC BEHAVIOR OF Co–Cr–B/Al2O3 IN HYDROGEN GENERATION BY HYDROLYSIS OF NaBH4

In this present study, the chemical reduction technique was used to synthesize Al2O3 supported Co-Cr-B catalyst (Co-Cr-B/Al2O3). The effects of the concentration of NaBH4, NaOH, amount of catalyst, ratio of metal/ Al2O3and temperature were discussed in detail. The results show that the reaction rate of hydrolysis first rises up and then goes down subsequently with the increase of NaBH4 concentration, as well as the concentration of NaOH. It was observed that the hydrogen generation rate increases with the molar content of metal changing from 2.5% to 5 wt%. However, when the metal/Al2O3 molar ratio is located from 5% to 20 wt%, the rate of hydrogen generation goes down. The hydrolysis kinetic order and the activation energy (????) of NaBH4 in the presence of Co-Cr-B/Al2O3 catalyst were found as 0.15 and 37.34 kJ*mol-1 , respectively. According to the results obtained, Co-Cr-B/Al2O3 catalyst can be used as a promising material in PEMFC mobile systems

Al2O3 supported co-cu-b ( Co-Cu-B/Al2O3) catalyst for hydrogen generatıon by hydrolysıs of aqueous sodıum borohydrıde (NaBH4) solutıons

In this study, Al2O3 supported Co-Cu-B (Co-Cu-B/Al2O3) catalyst was synthesized by chemical impregnation and precipitation method to be used for catalytic hydrogen generation from NaBH4. Co-Cu-B/Al2O3 catalyst was synthesized at various ratios using Co-Cu-B/Al2O3 (5-20%). The effect of some parameters such as NaOH concentration (0- 7%), NaBH4 concentration (2.5-7.5%), catalyst amount (25-150 mg) and solution ambient temperature was investigated on the catalytic hydrolysis of NaBH4. The hydrogen generation rate was found as 2519 and 8962 mL*g-1 *min-1 for Co-Cu-B and Co-CuB/Al2O3 catalysts in NaBH4 hydrolysis, respectively. The order rate kinetics and activation energy for Co-Cu-B/Al2O3 catalyst were determined as 0.125 and 27 kJ*mol-1 , respectively. The obtained results suggest that Co-Cu-B/Al2O3 catalysts can be used for mobile applications of PEMFC systems