| Abstract Scope |
Here, we report that incorporation of iron hydroxide into Pd18.3Pt11W1 (PPW-14) ternary alloy nanocatalysts boosts electrocatalytic activity of the oxygen reduction reaction (ORR). Iron hydroxide incorporation into PPW-14 alloy catalysts modifies the catalyst surface by exposing more active metal-hydroxide interface sites. The small quantity of W and Fe in the core-shell contributed to surface reconstruction, modifying the electronic structure of surface-active sites. Consequently, numerous defects were created on the surfaces, enhancing both electrochemical activity and durability. In addition, the chemical states of incorporated iron in the core-shell structure under ORR condition were evaluated through the construction Pourbaix diagrams using first-principles calculations of various iron hydroxide nanostructures on PdPt(111). The iron hydroxide interfacial sites served as active sites for ORR intermediate adsorption, effectively modulating OH and OOH binding free energies. The iron hydroxide decoration contributed to the observed synergistic effects in nanocatalysts, which also improved stability of catalyst. |