Double-Shell Co₃O₄ with Rich Surface Octahedron Oxygen Vacancies for High-Selectivity Electrocatalytic Chlorine...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Developing efficient non-noble metal catalysts for the chlorine evolution reaction (CER) is a significant challenge.
• Existing catalysts often struggle with activity, kinetics, and selectivity.

Purpose of the Study:

• To design and synthesize novel non-noble metal catalysts for enhanced CER performance.
• To investigate the role of surface oxygen vacancies and hierarchical nanostructures in catalyst activity.

Main Methods:

• Synthesis of hierarchical double-shell Co3O4 nanospheres with abundant surface oxygen vacancies (DS-Co3O4-OVs) using a morphology self-evolving strategy.
• Electrochemical characterization to evaluate catalytic activity, kinetics, and selectivity for CER.
• Density functional theory (DFT) calculations to elucidate the catalytic mechanism and the role of oxygen vacancies.

Main Results:

• DS-Co3O4-OVs achieved an overpotential of 52 mV at 10 mA cm-2 with excellent chlorine selectivity (98.9-99.9%).
• The performance surpassed that of commercial RuO2/IrO2 catalysts.
• DFT calculations confirmed that oxygen vacancies enhance CER kinetics by modifying reaction pathways and improving the Volmer step.

Conclusions:

• Hierarchical double-shell Co3O4 nanospheres with surface oxygen vacancies represent a promising non-noble metal catalyst for CER.
• The strategy of engineering surface octahedron oxygen vacancies offers a novel design approach for advanced CER catalysts.
• Understanding the interplay between nanostructure, oxygen vacancies, and reaction mechanisms is key to catalyst development.