Controlled Preparation and Anti‐Sulfate Electrocatalysis of Self‐Assembled Multidimensional PtZn Quasi‐Cubic Nanodendrites

Abstract

The multidimensional PtZn quasi‐cubic nanodendrites (PtZn‐ND) with tremendous amounts of defectively coarse branches, having both highly active high‐index facets and short‐range (100) and (110) terraces resisted to sulfate, are synthesized via facile oil phase route at first time. The growth process is found to start from Pt nano‐cuboid seeds, then PtZn nanoclovers which are formed from epitaxial growth, and then the flower‐like PtZn crystals and finally the novel PtZn‐ND. The formation mechanism of PtZn‐ND, in particular the effects of hexadecyltrimethyammonium bromide (CTAB) and oleic acid (OA) on the morphology, crystal shape and exposure lattice facets, have been comparatively and systematically studied. And it turns out that CTAB mainly controls depositing directions, while OA mainly controls the crystal shape/size. The combination effect results in unique PtZn‐ND structures. The novel PtZn‐ND also displays superior catalytic performance and anti‐sulfate poisoning ability. In particular, the mass activity (MA) and specific activity (SA) are 5.72 and 7.55 times higher than those of commercial Pt/C, and still 2.91 and 5.09 times higher after accelerated durability tests in 0.5 m H2SO4 for oxygen reduction reaction.

Introduction of Surface Modifiers on the Pt-Based Electrocatalysts to Promote the Oxygen Reduction Reaction Process

“…Conventionally, it was believed that the attachment of organic molecules to the surfaces of the electrocatalysts would limit the ORR process due to surface coverage and reduced conductivity [38,54]. Therefore, various measures were employed to remove the surfactants and organic reactants after the synthesis of the electrocatalysts to expose enough active sites [55,56].…”