• Gunasooriya, G. T.
• Zeledón, José A. Zamora
• Gallo, Alessandro
• Nørskov, Jens K.
• Kreider, Melissa E.
• Jaramillo, Thomas F.
• Hahn, Christopher
• Landers, Alan T.
• Stevens, Michaela Burke

Abstract

Alloying is a powerful tool that can improve the electrocatalytic performance and viability of diverse electrochemical renewable energy technologies. Herein, we enhance the activity of Pd-based electrocatalysts via Ag-Pd alloying while simultaneously lowering precious metal content in a broad-range compositional study focusing on highly comparable Ag-Pd thin films synthesized systematically via electron-beam physical vapor co-deposition. Cyclic voltammetry in 0.1 M KOH shows enhancements across a wide range of alloys; even slight alloying with Ag (e.g. Ag0.1Pd0.9) leads to intrinsic activity enhancements up to 5-fold at 0.9 V vs. RHE compared to pure Pd. Based on density functional theory and x-ray absorption, we hypothesize that these enhancements arise mainly from ligand effects that optimize adsorbate-metal binding energies with enhanced Ag-Pd hybridization. This work shows the versatility of coupled experimental-theoretical methods in designing materials with specific and tunable properties and aids the development of highly active electrocatalysts with decreased precious-metal content.

Topics

• Deposition
• density
• impedance spectroscopy
• theory
• thin film
• Oxygen
• density functional theory
• cyclic voltammetry