Preparation and electrocatalytic properties of Pd-Sn-Co nanoparticles modified reduced graphene oxide/CuBi₂O₄ composites

Trimetallic Pd-Sn-Co nanoparticles (NPs) were successfully fixed on the support graphene oxide (GO)/CuBi₂O₄ via facile hydrothermal and impregnation-reduction methods. The Pd-Sn-Co@reduced graphene oxide(rGO)/CuBi₂O₄ catalysts obtained were employed to the electrocatalytic oxidation of ethylene glycol (EG) in an alkaline medium. Compared with the monometallic Pd, bimetallic Pd-Co, Pd-Sn@rGO/CuBi₂O₄ electrocatalysts, the trimetallic Pd-Sn-Co@rGO/CuBi₂O₄ exhibits the highest electrocatalytic activity and tolerance of poison species, the forward peak current density as high as 186.54 mA·cm⁻², is about 6.3 times higher than that of commercial Pd/C (29.57 mA·cm⁻²). The outstanding electrooxidation performance of Pd-Sn-Co@rGO/CuBi₂O₄ composites is attributed to the unique 3D structures of support GO/CuBi₂O₄ which provide plenty of interfaces and achievable reaction active sites for the loading metals, as well as the strong synergistic effects of the well-dispersed Pd-Sn-Co NPs. Besides, the introduction of GO in CuBi₂O₄ matrix conduces to the loading of multi-metal NPs resulting in more adsorption of oxygenated species, and provides superior electron transfer and improves contact surface area with EG molecules. The study on the new composites offers a conception and applicable way to develop the advanced Pd-based electrocatalysts for high performance direct alcohol fuel cells.