Study of Cobalt Preciouses Effect on Impregnation Method and Characteristic Properties of Co-B Catalysts

Abstract

Due to its non-toxic, environmental friendly, availability to easily and low cost production, hydrogen is recognized as competitive alternative energy to fossil fuels [1]. Hydrogen could be stored as a compressed gas, as a liquid, in a chemical compound (e.g., chemical hydrides or metal hydrides), or physically hold within nanoporous structures [2].  The Co-B catalysts are known optimal catalyst as not only with its activeness for hydrolysis reaction of chemical hydrides (NaBH₄, NH₃BH₃ etc.) but also its economic cost [3].

In this study, cobalt preciouses effect on characteristic properties of Co-B catalysts were investigated. The Co-B catalysts were prepared from different sources of cobalt such as cobalt(II)chloride (CoCl₂.6H₂O), cobalt sulfate (CoSO₄.5H₂O) and cobalt(II)nitrate (Co(NO₃)₂.6H₂O) and boron source as boric acid (H₃BO₃) with Co:B 0.01:0.05 molar ratio. The Co-B catalysts were obtained by impregnation method subsequent heat treatment at 500^oC for 4 hours. The characterizations of the catalysts were clarified via XRD, BET and SEM. By the effect of different sources were determined changings in properties of Co-B catalysts. It was found that the catalysts were synthesis from CoCl₂.6H₂O had larger surface area than other Co sources. Co(NO₃)₂.6H₂O were formed amorphous structure while other Co sources were formed crystalline structures. Usage of different cobalt preciouses were led to interval distribution in particle size. In conclusion, we suggested to use CoCl₂.6H₂O as cobalt source for syntheses the Co-B catalysts.