2Department of Chemical Engineering, Yıldız Technical University, Istanbul, Türkiye; Clean Energy Technologies Institute, Yıldız Technical University, Istanbul, Türkiye
Abstract
Hydrogen became zero-carbon fuel used in fuel-cell or internal combustion engines, regarding energy sector green-hydrogen also has become an energy carrier in commercial applications. For supporting decarbonization strategies based on hydrogen, boron-fuels are good options to safely store for mobile technologies. Ammonia borane (NH3BH3) is the one of the boron based fuels that stored 19.6 wt.% H2 in its structure chemically. Cobalt (Co) decorated
egg-shell-type activated carbon pellets were synthesized for catalytic application of hydrogen release from NH3BH3. Two different sized pellet type activated carbon was decorated with cobalt by combined procedure as modified vacuum-impregnation method with heat fixation and reduction. The obtained catalysts were characterized by applying optical microscope (OM),
scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDS), transmission electron microscopy (TEM), nitrogen sorption based surface analyses (BET). Activated carbon provides porous structure for effectively dispersion Co particles while the outer shell shows the catalytic activity for hydrogen generation. Structural characterization results and
preliminary activity tests confirmed that fabricated Co@ACPB exhibited better performance compared with Co@ACPS catalysts thanks to thinner shell thickness and higher BET surface area/pore volume properties. The results of the kinetic study showed the core-shell type Co based catalyst catalyzed the reaction and follows the zero-order reaction kinetic model with
41.78 kJmol-1. Activated carbon pellets provide well dispersion and stability of active Co sites, easy separation of used catalysts after the reaction and enable practical regeneration of catalytic materials.