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

Abstract

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/Al2O3 and 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 (E-a) 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.