Edge Enrichment of Ultrathin 2D PdPtCu Trimetallic Nanostructures Effectuates Top-Ranked Ethanol Electrooxidation.

Atomic edge sites on two-dimensional (2D) nanomaterials display striking catalytic behavior, whereas edge engineering for 2D metal nanocatalysts remains an insurmountable challenge. Here we advance a one-pot synthesis of ultrathin 2D PdPtCu trimetallic nanosheets and nanorings with escalating low-coordinated edge proportions from 11.74%, 23.11% to 45.85% as cutting-edge ethanol oxidation reaction (EOR) electrocatalysts. This in situ edge enrichment hinges on a competitive surface capping and etching strategy with integrated manipulation of the reaction kinetics. Electrocatalysis tests demystify an edge-relied EOR performance, where the edge-richest 9.0-nm-Pd61Pt22Cu17 nanorings attain an exceptional activity (12.42 A·mg-1Pt+Pd, 20.2 times that of commercial Pt/C) with substantially improved durability. Molecularly mechanistic studies certify that the unsaturated edge sites on these 2D catalysts prevail, triggering the C‒C bond scission and succeeding CO removal to facilitate 12-electron-transferring EOR process. This study introduces the "Metal-Edge-Driven" concept and enables the "Edge Sites On 2D Multimetallic Nanocatalysts" technique to design versatile heterocatalysts.