Enhanced Ru Utilization with High Stability of (RuxCoy)Se2/C Electrocatalyst toward Oxygen Reduction Reaction

The ruthenium (Ru) precursor was introduced into carbon supported cobalt selenide (CoSe2/C) nanoparticles, which were prepared via a simple microwave route, to obtain the ternary carbon supported ruthenium cobalt selenide (RuCoSe/C) nanoparticles by chemical reduction of Ru on the CoSe2/C surface. Upon the subsequent heat treatment of RuCoSe/C at 400 degrees C a small amount of Ru introduced substituted some Co sites in the CoSe2 through the phase transformation of orthorhombic to cubic CoSe2, which led to the formation of a new cubic phase of (RuxCo1-x)Se-2/C. The half-wave and onset potentials were 0.68 V and 0.88 V (vs. RHE), respectively, in 0.1 mol. L-1 perchloric acid (HClO4) solutions. The mass activity was as high as 0.09 mA. mu g(-1) Ru at 0.75 V, which is comparable to that of the commercial Pt/C (0.10 mA.mu g(-1) Pt). Only 15 mV loss in the half-wave potential was observed after 1000 cycles in 0.1 mol. L-1 HClO4, suggesting the efficient Ru utilization and excellent electrocatalytic stability.