Kinetic Evaluation and Fabrication of Co-Fe-B Catalyst in Ethanol for Rapid Hydrogen Production From Sodium Borohydride.

In this study, Co-Fe-B catalysts were synthesized separately in ethanol and aqueous media under ambient conditions using a chemical reduction-precipitation method for rapid and efficient hydrogen generation from sodium borohydride (NaBH4) hydrolysis. The structural and morphological properties of the synthesized catalysts were characterized by SEM-EDX and XRD analyses. The results demonstrated that the synthesis medium had a significant influence on the catalytic performance. At 30 °C, the hydrogen generation rate of the Co-Fe-B catalyst synthesized in ethanol reached 13,021.6 mL gcat-1 min-1, whereas the catalyst synthesized in water exhibited a hydrogen generation rate of 4005 mL gcat-1 min-1 under the same conditions. The hydrogen generation rate increased with increasing temperature, catalyst amount, and NaBH4 concentration. The reaction order was determined to be approximately 0.9, and the activation energy of the highly active catalyst was calculated as 37.72 kJ mol-1 using the Arrhenius equation. The enhanced catalytic activity of the catalyst synthesized in ethanol was attributed to the formation of a larger active surface area and electron transfer from boron to the active Co and Fe sites. These findings reveal that the synthesis medium plays a critical role in determining the structural properties and hydrogen generation performance of Co-Fe-B catalysts.