Water-Based Synthesis of Palladium Trigonal Bipyramidal/Tetrahedral Nanocrystals with Enhanced Electrocatalytic Oxidation Activity

Well-defined palladium trigonal bipyramidal/tetrahedral nanocrystals were synthesized by an aqueous-phase hydrothermal method. The final products were a mixture of trigonal bipyramidal and tetrahedral nanocrystals. Statistics indicated that there were more trigonal bipyramids than tetrahedra in the products. Ethylenediamine tetraacetic acid disodium salt (EDTA-2Na) was proven to be essential in controlling the final shapes of palladium nanocrystals. Some control experiments were also conducted to investigate the shape evolution and formation mechanisms. The synthesized palladium nanocrystals showed enhanced catalytic properties for ethanol and glycerol electrooxidation in alkaline medium. This work provides a new method in preparing Pd nanomaterials with well-defined shapes.