Silica Support Affects the Catalytic Hydrogen Evolution by Silver

Silica supported silver nanoparticles, SiO₂-Ag⁰-NPs, catalyze the hydrolysis of BH₄⁻. A comparison of the isotopic composition of the hydrogen formed in the hydrolysis of BD₄⁻ points out that the contribution of hydrides, the Heyrovsky mechanism, rather than that of hydrogen atoms, the Tafel mechanism, to the hydrogen evolution is considerably larger for the SiO₂-Ag⁰-NPs catalyzed process than for the Ag⁰-NPs catalyzed process. This indicates some electron transfer from the SiO₂ to the silver that increases the negative charge on the Ag⁰-NPs.