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

Abstract

The ruthenium (Ru) precursor was introduced into carbon supported cobalt selenide (CoSe 2 /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 CoSe 2 /C surface. Upon the subsequent heat treatment of RuCoSe/C at 400 ℃, a small amount of Ru introduced substituted some Co sites in the CoSe 2 through the phase transformation of orthorhombic to cubic CoSe 2 , which led to the formation of a new cubic phase of (Ru x Co 1-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 (HClO 4 ) solutions. The mass activity was as high as 0.09 mAg -1 Ru at 0.75 V, which is comparable to that of the commercial Pt/C (0.10 mAg -1 Pt). Only 15 mV loss in the half-wave potential was observed after 1000 cycles in 0.1 molL -1 HClO 4 , suggesting the efficient Ru utilization and excellent electrocatalytic stability.