Copper nanoparticle exsolution from Sr(Ti, Fe)O₃ perovskites: material tuning and probing (electro)catalytic...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Copper (Cu) is a key catalyst for energy transition reactions but faces challenges in stability and performance.
• Exsolution offers a method to create stable, size-controlled metal nanoparticles on oxide supports.
• Perovskites like Sr(Ti, Fe)O3-γ are promising supports but require modification for efficient nanoparticle exsolution.

Purpose of the Study:

• To develop a novel method for controlled copper nanoparticle exsolution from Sr(Ti, Fe)O3-γ perovskites.
• To investigate the influence of exsolution parameters on nanoparticle characteristics and catalytic activity.
• To establish these materials as tuneable platforms for electrochemical applications.

Main Methods:

• Synthesis of Cu-doped Sr0.95Ti0.3Fe0.7-x CuxO3-γ perovskites.
• Controlled exsolution of Cu nanoparticles via low-temperature reduction (400 °C).
• Systematic variation of reduction parameters to control nanoparticle size and density.
• Electrochemical characterization using nitrate reduction reaction (NO3RR) as a probe.

Main Results:

• Achieved controlled exsolution of Cu nanoparticles at a mild temperature of 400 °C.
• Demonstrated control over nanoparticle size (13-38 nm) and population density (118-650 particles/µm²).
• Showcased the direct correlation between exsolution conditions, surface reactivity, and catalytic performance in NO3RR.

Conclusions:

• Cu exsolution from modified perovskites provides a stable and tuneable catalytic system.
• Low-temperature exsolution offers a milder route to high-performance electrocatalysts.
• These materials show significant potential for energy conversion applications, including nitrate electroreduction.