Surfactant-Assisted Synthesis of Polycrystalline Binary PdBi Alloy Nanoparticles for Ethanol Electrooxidation

The morphology and compositional modulation of palladium-based nanomaterials are of paramount importance in enhancing the catalytic performance of the ethanol oxidation reaction (EOR). In this study, we employed a simple oil bath method to synthesize PdBi alloy nanoparticles (NPs), maintaining the same elemental ratio. The size of the NPs could be modulated by varying the surfactant dosage. The synthesized PdBi alloys exhibited alterations in the d-band center of Pd, which were attributed to strain and ligand effects. These alterations subsequently affected the adsorption energy of the catalyst surface for the reaction intermediates. The current density of the Pd₉Bi/200 NP in the ethanol oxidation reaction was found to be as high as 1042.0 mA mg^-1, which is approximately twice that of Pd/C (508.0 mA mg^-1). This enhanced activity can be attributed to the modification of the electronic structure and morphology, which enables the material to possess a larger electrochemically active surface area (ESCA), thus providing a substantial number of active sites for the catalytic reaction. Furthermore, the experimental data indicated that increasing the electrocatalytic temperature, pH, and ethanol concentration could accelerate the electrooxidation rate of the EOR. This study presents an effective approach for investigating the role of surfactants in the synthesis of nanomaterials and enhancing the activity and stability of noble metal catalysts.