Decomposition of NaBH₄ with self-regeneration of carbon-supported CoCl₂ catalyst

Abstract

In this study, economically favorable CoCl2 catalysts at four different amounts were supported on activated carbon (AC) for NaBH4 dehydrogenation. Supported catalyst could achieve hydrogen release for 2,060 cycles, which is equivalent to 103 days of uninterrupted operation. Slow and continuous hydrogen release was observed in all experiments. Even 1 g of NaBH4 can carry 1.2 L of hydrogen, and in hydrolysis process, it liberates 2.5 L of hydrogen that indicates the decomposition of water. EDX analysis and reverse burette measurements show that CoCl2 could be homogeneously distributed on and permanently joined to the support surface. Kinetic investigation of the dehydrogenation reaction fits zero order kinetics, and activation energy was calculated to be 48 kJ/mol.