Catalytic dehydrogenation of calcium borohydride by using hydrogel catalyst

The aim of this study was to investigate dehydrogenation of calcium borohydride (Ca(BH4)(2)) in the presence of a catalyst. Co ion-loaded poly(acrylamide-co-acrylic acid) (p(AAm-co-AAc)-Co) hydrogel was taken as a catalyst for this dehydrogenation procedure. Dehydrogenation reactions were performed under three different reaction temperatures, so the rate order and activation energy of the reaction were determined by using experimental results. The amount of hydrogen production increased with temperature and yields of the dehydrogenation reactions were determined as 46.5, 76.0 and 98.5% for 25, 35 and 45 degrees C, respectively. The activation energy of the dehydrogenation of Ca(BH4)(2) was found as 71.39 kJ/mol according to zero order reaction kinetic. In addition, in order to determine reusability of p(AAm-co-AAc)-Co hydrogel, the same catalyst system was used in ten consecutive runs for the hydrolysis of Ca(BH4)(2). This catalyst system was used ten times without any structural defect of the catalyst. On the other hand, the conversion ratio decreased from 98.5% to 83.5%. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.