Platinum-Iridium-Ruthenium Trimetallic Alloy Nanoparticles as Catalysts for Oxygen and Hydrogen Evolution

The development of platinum (Pt)- or iridium (Ir)-based noble metal alloy catalysts is becoming increasingly important in improving the efficiency of water electrolysis reactions. In this study, PtIrRu trimetallic alloy nanoparticles with high activity and stability for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) were synthesized using an antisolvent crystallization-based method. The synthesized spherical Pt₂₃Ir₄₂Ru₃₅ alloy nanoparticles leverage the synergistic effects of multiple metals and the small size effect, featuring high dispersion, and a large surface area that maximizes exposing numerous active sites and enhances ion and electron transport rates. Additionally, their sizes were maintained regardless of the ratio of the Pt/Ir/Ru precursors. The integration of diverse metals with exceptional electronic properties is essential for designing and preparing catalysts with enhanced catalytic activity and stability. The activity and stability enhancements could be attributed to the inserted Ru, which effectively modified the electronic structure and improved the electron transfer among Pt, Ru, and Ir. Pt₂₃Ir₄₂Ru₃₅/C exhibited remarkable activity at a high current density of 50 mA·cm^-2 for the OER for at least 120 h. Further, it also exhibited outstanding HER performance with an overpotential of 26.6 mV at 10 mA·cm^-2, along with high durability lasting for 50 h.