Spontaneous hydrolysis of borohydride required before its catalytic activation by metal nanoparticles

Abstract

Though borohydride has been frequently used as a hydrogen source in the nanoparticle-catalyzed chemical reduction, the explanation for a delay of the reaction is still under debate. Here we investigated the mechanism of the catalytic borohydride reduction and found that the negative charge of borohydride prevented it from approaching the negatively charged nanoparticles, resulting in a delay of reactions. Spontaneous hydrolysis of borohydride was critical to the start of the reaction. A universal method was introduced to dramatically increase the catalytic efficiency. Our experiment suggested a guideline for designing efficient catalysts and reducing agents in future.