Cerium-optimized platinum-free high-entropy alloy nanoclusters for enhanced ampere-level sustainable hydrogen generation

The incorporation of rare earth (RE) elements into high-entropy alloys (HEAs) as electrocatalysts for hydrogen evolution reaction (HER) shows great potential in addressing the energy crisis. Here, we successfully synthesized cerium (Ce)-tailored PdCeMoCuRu HEA with chemical homogeneity and stability using a facile wet-chemical synthesis strategy. The obtained PdCeMoCuRu HEA provides abundant active metal sites, resulting in superior HER performance compared to state-of-the-art Pt/C. It only requires 12.8 mV to achieve a current density of 10 mA cm, which is nearly half that required for Pt/C (24.8 mV). Importantly, it exhibits excellent electrocatalytic durability for 100 hours even under a high current density of 1.0 A cm at the ampere level. Density functional theory (DFT) calculations confirm that the introduction of Ce can modify the electronic configuration and generate synergistic effects around Pd, Cu, and Ru active sites. This work establishes a novel approach for designing efficient RE-tailored HEA electrocatalysts.