Co supported on Manganese Ferrite for Hydrogen Evolution via Sodium Borohydride Hydrolysis

The generation of hydrogen gas through the catalytic hydrolysis of sodium borohydride (NaBH ₄ ) has garnered significant interest in recent years. The primary research challenge remains the development of effective and reusable catalysts. This research details the development of Co/MnFe ₂ O ₄ catalysts aimed at facilitating the hydrolysis of sodium borohydride (NaBH ₄ ), employing MnFe ₂ O ₄ as the support material. The support was synthesized through a co-precipitation method, while the catalysts were produced via an impregnation-chemical reduction technique. The characterization of the catalysts was performed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometry (VSM), and nitrogen adsorption-desorption measurements. The study initially explored the effects of calcination temperature of the supports and the amount of loaded cobalt on the hydrogen generation process. Notably, catalysts supported on MnFe ₂ O ₄ calcined at 400°C demonstrated superior activity, with 30% Co/MF-400 catalyst yielding 3533 mL.min ^− 1 .g _cat ⁻¹ of hydrogen during NaBH ₄ hydrolysis. The enhanced catalytic performance of the MF-400 supported catalysts was attributed to their small crystallite size or prominent number of defects and relatively high magnetic properties. In addition, 30Co-MF400 showed high specific surface area of 120.1 m ² .g ^− 1 . Subsequently, various parameters were examined over 30Co/MF-400, including catalyst dosage (10–20 mg), concentrations of NaOH (1–7 wt.%), temperature (25-45 ^o C), and catalyst reusability. The activation energy (E _a ) for the 30% Co/MF-400 catalyst was found to be 27.1 kJ/mol, as determined through the application of the rate expression and the Arrhenius equation. The 30% Co/MF-400 catalyst showed a 44% decline in catalytic performance after being used for four cycles.