PEI modified natural sands of Florida as catalysts for hydrogen production from sodium borohydride dehydrogenation in methanol.

Summary: Sand samples from Tampa (T) and Panama (P) City beaches in Florida were used as catalysts for dehydrogenation of NaBH4 in methanol. T and P sand samples were sieved to <250, 250 to 500, and >500 μm sizes, and the smallest fractions resulted in faster hydrogen generation rates (HGR), 565 ± 18 and 482 ± 24 mL H2 (min.g of catalyst)−1, respectively. After various base/acid treatments, HGR values of 705 ± 51 and 690 ± 47 mL H2 (min g of catalyst)−1 for HCl‐treated T and P sand samples were attained, respectively. Next, T and P sand samples were modified with polyethyleneimine (PEI) that doubled the HGR values, 1344 ± 103, and 1190 ± 87 mL H2 (min.g of catalyst)−1 and increased ~8‐fold, 4408 ± 187, and 3879 ± 169 mL H2 (min g of catalyst)−1, correspondingly after protonation (PEI+). The Ea values of T and P sand samples were calculated as 24.6 and 25.9 kJ/mol, and increased to 36.1, and 36.6 kJ/mol for T‐PEI+ and P‐PEI+ samples, respectively. [ABSTRACT FROM AUTHOR]