Investigating reaction conditions and kinetics for hydrogen production through boric acid catalysed methanolysis of potassium borohydride

This study explores hydrogen production via methanolysis of potassium borohydride (KBH₄) catalysed by boric acid (H₃BO₃) amidst growing demand for sustainable energy. It focuses on optimising reaction conditions to efficiently maximise hydrogen output. Parameters examined include reaction temperatures (20, 30, 40, 50°C), H₃BO₃ concentrations (53.9, 107.8, 161.7, 269.5 mM), methanol volumes (2, 5, 7, 15, 20 mL), and KBH₄ concentrations (0.124, 0.247, 0.371, 0.618 M), assessing their impact on hydrogen generation rates (HGRs). Kinetic analysis shows the reaction follows a power law mechanism with a reaction order of 0.5 for KBH₄, indicating a significant concentration dependency. The study identifies activation energies of 37.24 and 32.54 kJ·mol⁻¹, providing insights into the energy barrier of the reaction, and finds optimal conditions at 30°C, achieving a remarkable HGR of 3154.98 mL·min⁻¹·g cat⁻¹. ΔG°, ΔH_ads and ΔS° were also determined, further elucidating the reaction dynamics.