Electrocatalysis of peroxide reduction by Au-stabilized, Fe-containing poly(vinylpyridine) films

We show that poly(vinylpyridine) (PVP) coated glassy carbon surfaces containing Fe(CN)6(3-) exhibit catalytic activity toward electroreduction of H2O2. While Fe(CN)6(3-) is catalytically inactive in solution phase, it exhibits catalytic activity upon incorporation into the PVP film, because film incorporation leads to an open coordination site in the otherwise inert Fe(CN)6(3-) molecule. However, this catalytic activity is quickly lost during H2O2 electroreduction due to leaching of the Fe species from the PVP film. The Fe catalyst in the PVP film could be stabilized by 1 order of magnitude in time by electrodeposition of small Au particles. Characterization of the film using scanning electron microscopy, secondary ion mass spectroscopy, and Raman spectroscopy shows that covalent attachment between the Au particle and the Fe-based catalyst is a likely mechanism for catalyst stabilization.