Synergizing Strain and Ternary Components in Ultrathin PtCuIr-IrOx Nanodendrites to Enable the C2 Pathway for Ethanol Electrooxidation.

Efficient and selective ethanol electrooxidation to acetate is hindered by competing poisoning and overoxidation pathways. We address this through ultrathin PtCuIr-IrOx nanodendrites that integrate strain engineering with ternary functionality. The alloy core imposes compressive strain, downshifting the Pt d-band center to optimize adsorption, while the oxophilic IrOx phase supplies oxygenated sites that accelerate ethanol dehydrogenation and acetaldehyde-to-acetate conversion. In situ SERS confirms the preferential accumulation of acetate, while DFT calculations reveal near-thermoneutral adsorption of acetaldehyde, which can be driven by interfacial electron transfer via the C2 pathway. The catalyst shows enhanced activity, achieving a current density 3-fold higher than that of Pt/C, along with improved stability, maintaining a current density 4-fold higher than Pt/C after 3000 s of chronoamperometric testing. This work establishes the integration of strain-tuned alloys with oxophilic oxides as an effective strategy for steering reaction pathway preference in complex electrocatalysis.