Engineering PdIr Nanostructures Synergistically Induced by Self-assembled Surfactants and Halide Ions for Alcohol Electrooxidation

The design and synthesis of metallic nanocatalysts with distinct nanostructures and composition is still a noteworthy topic in the electrochemistry field. In this work, we have realized the morphological evolution of PdIr nanostructures in aqueous solution through the synergistic effect of self-assembled functional surfactants and different halide ions, and achieved precise control of the kinetic and thermodynamic crystalline growth due to the different reduction potential between PdCl₄^2?, PdBr₄^2?, and PdI₄^2?. The actual precursors of PdCl₄^2? resulted in ultrathin nanodendrites, PdCl_xBr_(4?x)^2? for nanosheets and fewer branched nanodendrites, PdCl_xI_(4?x)^2? for nanorings, nanoflowers and multiply concave nanocubes. Owing to the synergistic advantages of structure and composition (alloyed Ir), PdIr nanodendrites exhibited enhanced electrocatalytic activity, anti-poisoning ability, and stability toward alcohols (including ethanol, methanol, and glycerol) electrooxidation reactions. The results would be helpful for thoroughly understanding how structure-directing surfactants and halide ions synergistically determine the production of advanced metallic nanocrystals.