Quantifying Interface-Dependent Active Sites Induced by Topotactic Exsolution for CO₂ Electrolysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Supported metal nanoparticles formed via in situ exsolution are promising for CO2 electrolysis.
• Quantifying these interfacial sites for intrinsic activity is challenging.

Purpose of the Study:

• To quantitatively analyze the exsolution process and normalize interfacial sites to intrinsic activity.
• To tailor CoFe/La0.6Sr0.4Cr0.9Co0.1O3-δ (LSCC) interfaces for controlled nanoparticle exsolution.

Main Methods:

• Topotactic ion exchange strategy to control exsolved CoFe nanoparticle coverage.
• X-ray absorption spectroscopy and Mössbauer spectroscopy to investigate Fe's role.
• Quantitative correlation analysis between interfacial parameters and CO2 electrolysis performance.

Main Results:

• Fe concentration modulation precisely controls exsolved CoFe nanoparticle coverage.
• Fe facilitates Co cation exsolution.
• CO2 electrolysis performance shows a linear positive correlation with the CoFe/LSCC interface perimeter.

Conclusions:

• Achieved peak performance of 1.73 A cm-2 at an optimal interfacial perimeter of 29.3 μm μm-2.
• Provides insights into quantitative analysis of metal/oxide catalysts for CO2 electrolysis.