  Pt electrocatalytic nanoparticles were deposited onto hybrid carriers
composed of reduced graphene oxide (rGO)-transition metal hexacyanoferrate
(Prussian Blue-PB) and the resulting system's electrochemical activity was
investigated during oxygen reduction reaction in acidic solution. The Prussian
Blue -utilizing and Pt nanoparticle-containing materials were characterized
using transmission electron microscopy, X-ray diffraction and electrochemical
diagnostic techniques such as cyclic voltammetry and rotating ring-disk
voltammetry. Application of rGO carriers modified with Prussian Blue as
matrices (supports) for Pt catalytic centers does not change practically the
potential of electroreduction of oxygen in 0.5 mol dm-3 H2SO4 (under rotating
disk voltammetric conditions) relative to the behavior of the analogous PB-free
system. What is even more important that, due to the presence of the
polynuclear cyanoferrate modifier, the amounts of the undesirable hydrogen
peroxide intermediate are significantly decreased (at ring in the rotating
ring-disk voltammetry). The results are consistent with the bifunctional
mechanism in which oxygen reduction is initiated at Pt centers and the hydrogen
peroxide intermediate is reductively decomposed at reactive PB-modified rGO
supports.
