Co/Fe3O4@GO catalyst for one-step hydrogen generation from hydrolysis of NaBH4: Optimization and kinetic study

In this study, cobalt nanocatalysts supported on the Fe3O4@GO were synthesized for boosting hydrogen generation upon hydrolysis of sodium borohydride. Co/Fe3O4@GO cat-alysts were synthesized through a facile co-precipitation method followed by a chemical reduction step. The prepared samples were characterized using various techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Vibrating sample magnetometer (VSM), and Nitrogen adsorption-desorption (BET). Benefiting from the high crystallinity, good dispersion of Co nanoparticles over the Fe3O4@GO, and the synergistic effect between Co nanoparticles and Fe3O4@GO support, Co/Fe3O4@GO catalysts with 30 wt% cobalt loading showed the highest catalytic activity with high hydrogen generation rate of 4000 mL/ min.gcat and relatively good stability. To investigate the effect of the parameters on hydrogen generation rate and optimal reaction conditions, the Box-Behnken design under response surface methodology (RSM) was applied. ANOVA results denoted that the temperature with the highest F-value and lowest P-value had the most effect on the hydrogen generation rate. Under the optimum conditions including a temperature of 39.83 degrees C, 17.74 mg of catalyst, and 5.135 wt% NaBH4 concentration, Co(30%)/Fe3O4@GO exhibited a superior H2 generation rate of 6005 mL/min.gcat and low activation energy of 44.4 kJ/mol. Therefore, the Co/Fe3O4@GO is a promising catalyst for NaBH4 hydrolysis due to its easy preparation and separation method, high hydrogen generation rate, and low activation energy. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.