Interfacial Pd-O-Ce Linkage Enhancement Boosting Formic Acid Electrooxidation.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Metal-support interactions are crucial for catalyst performance in fuel cells.
• Optimizing these interactions can enhance catalytic activity and durability.

Purpose of the Study:

• To investigate the effect of substrate morphology and thermal annealing on Palladium@Cerium dioxide (Pd@CeO₂) catalysts for formic acid electrooxidation.
• To elucidate the mechanism of Palladium-Oxygen-Cerium (Pd-O-Ce) linkage enhancement.

Main Methods:

• Synthesis of Pd supported on three different CeO₂ nanocrystal morphologies.
• Characterization using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy.
• Electrochemical testing for formic acid oxidation and CO poisoning resistance.

Main Results:

• Pd@CeO₂ catalysts on CeO₂ plates exhibited superior performance due to high oxygen vacancy and Ce³⁺ content.
• Thermal annealing in N₂ atmosphere significantly strengthened Pd-O-Ce linkages.
• Annealed Pd@CeO₂-plate catalysts showed a 1.93-fold increase in mass activity and improved stability.

Conclusions:

• Substrate morphology and thermal annealing are effective strategies to enhance metal-support interactions.
• Strengthened Pd-O-Ce linkages improve catalytic activity, kinetics, and anti-CO poisoning ability in formic acid electrooxidation.
• Formation of effective Pd-O-Ce linkages requires inert atmosphere conditions for optimal fuel cell catalyst design.