Highly efficient acid-treated cobalt catalyst for hydrogen generation from NaBH4 hydrolysis

The effect of cobalt-based catalysts, i.e. CoCl2(20 wt% Co)/Al2O3 treated by different acids, on NaBH4 hydrolysis was investigated. Five acids were used: oxalic acid, citric acid, acetic acid, sulfuric acid and hydrochloric acid. Two ways of acid treatment were considered: (i) ex-situ addition of acid to CoCl2(20 wt% Co)/Al2O3 at room temperature and (ii) in-situ addition by mixing CoCl2, Al2O3 and acid (one-step process). Both ways showed that adding an acid to the catalyst contributed to an important increase of the catalytic activity towards the NaBH4 hydrolysis. The best performances were obtained with the catalysts treated with either HCl or CH3COOH as the global activity of CoCl2(20 wt% Co)/Al2O3 was increased up to 50%.