FUEL, cilt.305, 2021 (SCI-Expanded)
In this study, the catalyst produced from tea factory waste (TFW) was used for the first time for hydrogen production by methanolysis of sodium borohydride (NaBH4). The produced material had a dual function as both catalyst and supercapacitor; therefore, it was named 'cap-cat'(capacitor-catalyst) by us. In this context, TFW was treated with acetic acid for 24 h at 80 degrees C. The sample was then subjected to combustion in the oven to synthesize the catalyst. Afterward, the most efficient TFW-CH3COOH catalyst was synthesized by evaluating different acid ratios, burning temperatures and times. The best conditions for the acetic acid ratio, burning temperature, and time were found out 3 M, 300 degrees C, and 60 min. The characterization of the catalyst was done using SEM-EDX, FTIR, XRD analysis. Hydrogen generation experiments from NaBH4 by methanolysis were performed at various catalyst concentrations in the range of 0.05-0.2 g, diverse NaBH4 ratio of 1 to 7.5%, and at different reaction temperatures (30-60 degrees C). The HGR of the synthesized catalyst was recorded as 3096.4, 8367.5, 11227.9, and 23,507 mLmin(-1)g(cat)(-1) for these temperatures (30, 40, 50, and 60 degrees C), respectively. Also the activation energy was calculated as 38.6 kJ mol(-1). Subsequently, the CV (cyclic voltammetry) and charge-discharge curves of the prototypes produced were substantially similar to the supercapacitor curves in the literature. Gravimetric capacitance was found to be 155F/g at a current density of 2 A/g.