Truncated octahedral platinum–nickel–iridium ternary electro-catalyst for oxygen reduction reaction

In present work, truncated octahedral Pt–Ni–Ir ternary nanoparticles with an average size of 10 nm and a Pt/Ni/Ir atomic ratio of 55/29/16 are synthesized through a facile method. Structural measurements show that the nanoparticles are surface Ni-scarce Pt–Ni–Ir ternary nanostructures. The mass activity and specific activity of the ternary catalyst are 511 mA mg−1 (Pt) and 1.03 mA cm−2 at 0.9 V (vs. reversible hydrogen electrode, RHE), respectively, which are nearly 4.8 and 6.0 times larger than that of the commercial Pt/C catalyst (106 mA mg−1 and 0.17 mA cm−2). After duration test of 10,000 cycles at the potential range from 0.6 to 1.0 V, the ternary catalyst preserved 66% and 73% of its initial mass activity and specific activity, respectively, which are 9 and 7.6 times that of the commercial Pt/C catalyst (37.2 mA mg−1 and 0.0998 mA cm−2, respectively) after the same durability examination. The dramatic enhancement of Pt–Ni–Ir ternary catalyst can be attributed to its morphology, composition and nanostructure. Our research suggests that Pt–Ni–Ir ternary catalyst could be an excellent candidate for ORR. Our investigation might also spur increasing attention to tailoring morphology and composition of ternary or multi-metallic nanostructure with high electro-catalytic performance.