Amplified Interfacial Effect in an Atomically Dispersed RuO_x -on-Pd 2D Inverse Nanocatalyst for High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Atomically dispersed oxide-on-metal inverse nanocatalysts offer enhanced heterocatalysis via strong oxide-metal interactions.
• Fabrication of such advanced nanocatalysts presents significant challenges.
• Developing efficient catalysts for the oxygen reduction reaction (ORR) is crucial for fuel cells and metal-air batteries.

Purpose of the Study:

• To report a novel 2D inverse nanocatalyst with atomically dispersed RuO_x on Pd nanosheets.
• To investigate the catalyst's performance in the oxygen reduction reaction (ORR) in an alkaline medium.
• To explore the underlying mechanisms of enhanced catalytic activity using theoretical calculations.

Main Methods:

• One-pot synthesis to create RuO_x/Pd nanosheets with in situ formed interfaces.
• Electrochemical testing to evaluate the catalyst's performance for the oxygen reduction reaction (ORR).
• Density functional theory (DFT) calculations to understand the electronic structure and adsorption properties.

Main Results:

• The RuO_x/Pd nanosheets exhibited significantly enhanced ORR activity, showing 8.0-fold and 22.4-fold higher mass activity compared to Pt/C and Pd/C, respectively.
• The catalyst demonstrated excellent potential as a platinum-alternative cathode electrocatalyst.
• DFT calculations confirmed that the RuO_x/Pd interface facilitates O-O bond cleavage and weakens oxygen binding by downshifting the d-band center of Pd.

Conclusions:

• The developed 2D RuO_x/Pd inverse nanocatalyst is a highly effective and promising material for ORR.
• This work provides a new fabrication strategy for advanced oxide-on-metal nanocatalysts.
• The findings pave the way for next-generation electrocatalysts in fuel cells and metal-air batteries.