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

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.