Activated carbon assisted cobalt catalyst for hydrogen production: synthesis and characterization

Abstract

In this work, a cobalt catalyst supported by activated carbon was used to produce hydrogen through the hydrolysis of sodium borohydride (NaBH4). First, hydrochar was produced from MDF powder by hydrothermal pretreatment. Then, ideal parameters (activator percentage, activation time, baking time, and temperature) for activated carbon production were determined. The best conditions for the synthesis of activated carbon were found to be a 70% activator rate, 24 hours of activation time, 45 minutes of baking time, and 700 ⁰C temperature, according to iodine number measurements. The iodine number was measured as 929 mg/g under optimum conditions. Activated carbon (as a support) produced under optimum conditions was combined with the cobalt catalyst. DT/TGA, FT-IR, SEM, and EDX analyses were used to evaluate the catalyst's structure. Supporting material ratio, NaOH concentration, catalyst amount, and NaBH4 concentration are the variables studied in catalyst synthesis. The trials led to the identification of the optimal catalyst parameters as being 70% support material, 5% NaOH, 40 mg catalyst, and 2% NaBH4 concentration. The hydrogen production rate with the catalyst synthesized in these conditions was determined as 8592.8 ml/g.min. As a result of the hydrolysis reactions carried out at different temperatures, it was determined that the reaction was n. order and the reaction activation energy was 31.19 kJ/mol. Even after the sixth use, 100% efficiency was attained when the catalyst activity was tested repeatedly.