Shape-Controlled Synthesis of Pd and PdPt Alloy Nanostructures by Electrodeposition for Electrocatalytic Ethanol Oxidation

Pd-based nanomaterials play a crucial role in fuel cells and electrosynthesis, particularly for electrocatalytic oxidation of small organic molecules. To enhance the catalytic performance of Pd-based catalysts, it is essential to precisely control both the surface atomic arrangement and the electronic structure. In this work, we carried out shape-controlled synthesis of Pd-based nanocrystals in alkaline media through an electrochemical square wave potential method. Various shaped nanocrystals with different index facets were prepared including {111}-faceted octahedral Pd nanocrystals (OH Pd NCs), {441}-faceted trisoctahedral Pd nanocrystals (TOH Pd NCs), {110}-faceted rhombic dodecahedral Pd nanocrystals (RD Pd NCs), octahedral PtPd nanocrystals (OH PtPd NCs), and {441}-faceted trisoctahedral PdPt nanocrystals (TOH PdPt NCs). The obtained Pd-based nanocrystals with varied surface structures and compositions were used as model catalysts to study the electrocatalytic activity for ethanol oxidation. The result revealed the following activity trend: OH PtPd NCs > OH Pd NCs > TOH PdPt NCs > TOH Pd NCs > RD Pd NCs. This study provides valuable insights into the effects of surface structure and alloying for ethanol oxidation on Pd-based catalysts, offering a strategy for the design of improved Pd-based catalysts.