Synergistic oxygen evolving activity of a TiO2-rich reconstructed SrTiO3(001) surface

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Catalyst performance is fundamentally linked to both composition and structure.
• Anomalous Ti oxide-rich surface phases, stabilized as epitaxial overlayers, exhibit distinct oxygen binding modes and reactivity.
• Ternary oxides offer tunable properties for catalytic applications.

Purpose of the Study:

• To investigate the impact of TiO2 double-layer surface reconstruction on the oxygen evolution activity of SrTiO3.
• To elucidate the fundamental mechanisms behind the enhanced catalytic performance.
• To demonstrate the predictive power of theoretical modeling in materials design.

Main Methods:

• Density functional theory (DFT) investigations to predict surface structures and properties.
• Electrochemical measurements to experimentally validate theoretical predictions.
• First-principles theoretical modeling for materials processing guidance.

Main Results:

• A TiO2 double-layer surface reconstruction was predicted and experimentally shown to enhance the oxygen evolving activity of SrTiO3.
• The enhanced activity is attributed to the presence of two distinct Ti sites with varying oxidation capabilities.
• A strong O-O moiety is formed, mitigating overbonding at Ti sites, facilitated by a labile lattice oxygen.

Conclusions:

• Surface reconstruction offers a viable strategy to improve the catalytic performance of established oxide catalysts.
• Theoretical modeling is a powerful tool for predicting and guiding the development of advanced catalytic materials.
• The identified mechanisms provide insights into optimizing oxygen evolution reactions on perovskite-type oxides.