Formation of Disordered High-Entropy-Alloy Nanoparticles for Highly Efficient Hydrogen Electrocatalysis

High-entropy-alloy nanoparticles (HEA NPs) show extraordinary performances for electrocatalytic hydrogen evolution and oxidations. Herein, two types of PtRhPdIrRu quinary HEA NPs with disordered and crystallized nanostructures were synthesized with and without the mixture boiling. Under vigorous boiling, HEA NPs with disordered structure in the size of 3.5 nm were synthesized due to the enhanced heat transfer and mass transfer. The disordered HEA (d-HEA) NPs exhibited ultrahigh turnover frequency of 33.1 s–1 at the overpotential of 50 mV, which was 5.4 times higher than commercial Pt NPs in the acidic electrolyte. Moreover, d-HEA shows much higher stability at the constant electrolyzing current of 50 mA cm–2 than commercial Pt NPs. In addition, d-HEA NPs as the anodic catalyst of H2-O2 fuel cell can output high current power density of 15.3 kW per gram noble metal. Therefore, the d-HEA NPs shed light on the hydrogen involved electrochemical application.