Kinetics of catalytic hydrolysis of NaBH4 solution: Ni-La-B catalyst

Abstract

In the present study, hydrolysis of NaBH4 was carried out in the presence of Ni-La-B catalyst, and its kinetic modeling was studied by the Coats-Redfern method. By setting up the system in microwave and non-microwave media, the hydrolysis reaction of NaBH4 was started and the hydrogen formed was measured as a function of time. Hydrolysis of NaBH4 to produce hydrogen was studied in the temperature range 30-80 degrees C. Parameters such as NaOH concentration, time efficiency and microwave power efficiency were examined, and activation energies and reaction degree n values were calculated for each step. When examined in terms of activation energy and NaOH effect, it was observed that the microwave media was more active. In the microwave media, the hydrogen production volume decreased as the NaOH concentration increased. In the non-microwave media, when the NaOH concentration was increased from 1.5 to 5%, the hydrogen volume increased and then decreased with increasing concentration. The activation energy for microwave (Power: 100 W, Heating rate: 2 degrees C/min) and non-microwave media was calculated as 69.920 and 70.544 kJ/mol, respectively. When the heating rate was 8.33 degrees C/min, the activation energy calculated for both media was 46.832 kj/mol (microwave) and 66.960 kj/mol (non-microwave). It was concluded that there are different mechanisms depending on the reaction order of n. The variation of the parameters in the conversion scope was discussed based on changes in solution properties during the progression of the hydrolysis reaction for both microwave and non-microwave media.