Preparation and eva‎luation of Cobalt and Iron based Nanocatalysts in Sodium Borohydride Hydrolysis Process

1/1/1900 12:00:00 AM

Sodium borohydride hydrolysis is one of the new and clean methods for hydrogen production that has recently been considered by researchers around the world. In this research, Co/CoFe2O4, Co and Co-Fe-B catalysts have been developed which showed good performance in environmental conditions and in the process of hydrolysis of sodium borohydride. The research of this collection was done in 3 sections. In the first part, cobalt ferrite catalyst was synthesized as the base of the catalyst through the mechanochemical method and then cobalt particles were added as the active sites by the wet impregnation method. The optimum active site in this catalyst was actually 7.5% cobalt, which was based on cobalt ferrite and its specific surface area was 8.95 m2/g. The maximum hydrogen generation rate at room temperature and activation energy for this catalyst were 1646.3 ml / (min.gcat) and 57.2 kJ/mol, respectively. This catalyst has a crystal structure with FCC crystal lattice. The catalyst was also tested in 5 consecutive cycles and showed good stability. In the second part of this study, pure cobalt catalysts were synthesized and tested by two methods, mechanochemical and chemical reduction, using different precursors. Between the two methods, the catalyst which were obtained through the chemical reduction method using oleic acid, showed a stronger activity. The maximum hydrogen generation rate at room temperature and the activation energy for this catalyst was 3272.7 ml / (min.gcat) and 22.3 kJ/mol, respectively. This catalyst was tested in 4 consecutive cycles and had an acceptable hydrogen generation rate. characterization analysis were then performed for all three catalysts. The results showed that the catalyst synthesized by the chemical reduction method using hydrazine is cobalt carbonyl and has a crystal structure with orthorhombic crystal lattice. In the third part, the Co-Fe-B catalyst was synthesized by the chemical reduction with different molar ratios of cobalt and iron. After eva‎luation of this catalyst, it was found that the optimal ratio of cobalt to iron was 6: 1, the maximum hydrogen generation rate at room temperature, and its activation energy were 3846.2 ml / (min.gcat) and 19.45 kJ/mol. The structure of this catalyst was amorphous and had good stability in catalyst recovery experiments.

هيدروليز سديم بوروهيدريد , سنتز كاتاليست كبالت خالص , سنتز كاتاليست مبتني بر كبالت و آهن , نانومواد

Sodium borohydride hydrolysis , synthesis of pure cobalt catalyst , synthesis of cobalt and iron based catalyst , nanomaterials

alireza kourang beheshti

prof. mehran rezaei and prof. seyyed mehdi alavi