Rapid synthesis of a highly dispersed FeCoNiRuPt high-entropy alloy bifunctional electrocatalyst and exploration of the catalytic mechanism

Abstract

The unique advantages and potential of high-entropy nanoalloys in catalysis are reflected in their ability to transcend the limitations of conventional single-component catalysts through elemental synergies. Herein, an electrocatalyst was synthesized via the microwave rapid heating method, consisting of FeCoNiRuPt high-entropy alloy nanoparticles supported on reduced graphene oxide. The electrocatalytic hydrogen evolution reaction performance of this sample in acidic and alkaline solutions significantly surpasses that of the commercial 20% Pt/C catalysts. Moreover, its oxygen evolution reaction performance in alkaline solution outperforms commercial IrO₂ catalysts. Microstructural characterization indicates that the superior hydrogen evolution reaction activity is attributed to enhanced electron transfer and surface element concentration gradients induced by the dissolution of transition metals during catalysis. For the oxygen evolution reaction, the performance enhancement is ascribed to the formation of a stable high-entropy oxyhydroxide layer on the alloy surface. Stability tests confirm that the catalyst maintains consistent performance for over 120 hours under both acidic and alkaline conditions. These findings highlight the significant potential of high-entropy alloys as bifunctional catalysts for efficient electrochemical water splitting.