Abstract
Designing electrocatalysts with high-performance for both reduction and oxidation reactions faces severe challenges. Here, the uniform and small size (~3.4 nm) high-entropy alloys (HEAs) Pt18Ni26Fe15Co14Cu27 nanoparticles (NPs) are synthesized by a simple low-temperature (<250 oC) oil phase synthesis strategy at atmospheric pressure for the first time. The Pt18Ni26Fe15Co14Cu27/C catalyst exhibits excellent electrocatalytic performance for hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The catalyst is one of the best performance achieved by state-of-the-art alkaline HER catalysts, which shows an ultrasmall overpotential of 11 mV at the current density of 10 mA cm-2, excellent activity (10.96 A mg-1Pt at -0.07 V vs. reversible hydrogen electrode) and stability in the alkaline medium. Furthermore, it is also the most efficient catalyst (15.04 A mg-1Pt) ever reported for MOR in alkaline solution. DFT calculations confirm the multi-active sites for both HER and MOR on the HEA surface as the key factor for both proton and intermediate transformation. Meanwhile, the construction of HEA surfaces supplies the fast site-to-site electron transfer for both reduction and oxidation processes.
Ag@Au Concave Cuboctahedra: A Unique Probe for Monitoring Au-Catalyzed Reduction and Oxidation Reactions by Surface-Enhanced Raman Spectroscopy
