Solvothermal Synthesis of PdPtCuRhRu High-Entropy Alloy Nanosheets for Advanced Alcohol Oxidation Reactions

Direct ethanol fuel cells (DEFCs) are increasingly appealing to researchers in diverse fields because of their advantageous characteristics: high energy density, low-temperature operation, and environmental sustainability. High-entropy alloy (HEA) has been one of the most promising materials to boost the alcohol oxidation reaction (AOR) that contributes significantly to the direct alcohol fuel cells (DAFCs). In this article, a two-step thermal solvent method was explored to synthesize PdPtCuRhRu HEA nanosheet assemblies (PdPtCuRhRu HEA NSA), to accelerate the methanol oxidation reaction (MOR) and the ethanol oxidation reaction (EOR). Prior to the synthesis of PdPtCuRhRu HEA NSA, PdPtCu NSA was fabricated, which provides a structural nanosheet assembly framework for the final HEA NSA. HEA NSA consists of stacked nanosheets with Rhodium (Rh) and Ruthenium (Ru) incorporated via a solvothermal method. Owing to its excellent physicochemical properties, strong multielement synergistic effects, and tunable electrocatalytic performance, the HEA NSA electrocatalyst achieves mass activities of 2208.1 and 2093.8 mA mgPd+Pt–1 for MOR and EOR, respectively. This study presents a feasible strategy for fabricating HEA NSA with excellent electrocatalytic performance, advancing the development of alloy catalysts for DAFC applications.