Acetic acid, a relatively green single-use catalyst for hydrogen generation from sodium borohydride

Acid-catalyzed hydrolysis of sodium borohydride (NaBH4) has been studied (reactivity and kinetics) at high acid concentration (0.32 M). A mineral (hydrochloric acid, HCl) and an organic benign (acetic acid, CH3COOH) acid have been chosen. Our study has three distinct objectives, namely: (i) combining the simplicity of the storage of solid NaBH4 with the simplicity of the aqueous solution of acid; (ii) showing CH3COOH can be as reactive as HCl in specific well-chosen operating conditions; and (iii) emphasizing the relative greenness of the CH3COOH-based process. All of these objectives have been fulfilled and show that CH3COOH is a benign relatively green acid catalyst of choice for catalyzing hydrogen generation from NaBH4, the acid–water–NaBH4 system being quite simple.