Cobalt-doped carbon spheres: Impact on potassium borohydride hydrolysis

Metal hydrides, which play a role both in hydrogen storage and in the production of hydrogen as a result of its reaction with water, have become materials intensively researched by scientists since also hydrogen has become a hot topic as a clean and renewable energy carrier. In this study, carbon sphere-supported Co catalyst was synthesized by the impregnation-chemical reduction method for the production of hydrogen by the hydrolysis of KBH₄, which is a good alternative to NaBH₄ but has not been studied much. Characterization of the synthesized catalyst was performed by XRD, BET, SEM (SE and EDX), TEM & DLS. The effects of parameters such as metal/support ratio, KBH₄ concentration, KOH concentration, catalyst amount and temperature on the hydrolysis reaction were investigated. The optimum metal/support ratio was determined as 10%Co/90%CS and the hydrogen production rate as a result of the hydrolysis of 1 wt% KBH₄ with 7 wt% KOH at 30 °C was calculated as 7149.2 mL min⁻¹.gcat⁻¹. According to the nth order kinetic model and the Langmuir-Hinshelwood model, the activation energies were calculated as 56.13 and 57.86 kJ/mol, respectively. Thus, it was found that the two models were consistent with each other and the degree of reaction was n = 0.26.