Comparative Study on the Electrocatalytic Performance of ABO₃-Based Hexagonal Perovskite Oxides with Different [AO₃]...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Hexagonal perovskite oxides are promising electrocatalysts.
• Understanding the structure-property relationship is crucial for optimizing performance.

Purpose of the Study:

• To investigate how the number of [BaO3] layers in hexagonal perovskite oxides affects oxygen evolution reaction (OER) performance.
• To synthesize and characterize new hexagonal perovskite oxides with varying [BaO3] layer numbers.

Main Methods:

• Sol-gel synthesis of 2H, 6H, and 10H-BaCo0.9Ru0.1O3-δ.
• Electrochemical testing for OER performance.
• In situ Raman spectroscopy for structural stability.
• Density Functional Theory (DFT) calculations for electronic structure.

Main Results:

• 10H-BaCo0.9Ru0.1O3-δ exhibited the highest OER activity and excellent structural stability.
• Increasing [BaO3] layers correlated with higher effective magnetic moments and increased surface Co ion valence.
• DFT calculations revealed a relationship between the p-band center (εp) and the number of [BaO3] layers, predicting performance.

Conclusions:

• The number of [BaO3] layers significantly influences the OER performance of hexagonal perovskite oxides.
• 10H-BaCo0.9Ru0.1O3-δ is a highly effective catalyst for the oxygen evolution reaction.
• This study provides insights for designing advanced hexagonal perovskite oxide electrocatalysts.