Zirconium-Doped Co₃O₄ for Enhancing the Acidic Oxygen Evolution Reaction by Triggering the Lattice Oxygen-Mediated Mechanism

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) in acidic media is vital for proton exchange membrane water electrolyzers (PEMWE).
• Spinel-type Co3O4 shows promise but is outperformed by precious metal catalysts.
• Enhancing Co3O4's activity and stability is key for practical PEMWE applications.

Purpose of the Study:

• To investigate the effect of zirconium (Zr) doping on the catalytic performance of Co3O4 for acidic OER.
• To explore the mechanism behind the enhanced activity and stability of Zr-doped Co3O4.

Main Methods:

• Synthesis of Zr-doped Co3O4 (ZrxCo3-xO4) nanoparticles.
• Electrochemical characterization of OER performance in acidic media.
• In situ electrochemical tests and theoretical calculations (e.g., DFT) to probe the reaction mechanism.

Main Results:

• Zr-doped Co3O4 (ZrxCo3-xO4) exhibits significantly enhanced catalytic activity and fast kinetics for acidic OER.
• The catalyst demonstrates excellent stability, maintaining 100 mA cm-2 for 60 hours.
• Zr doping triggers the lattice oxygen-mediated mechanism (LOM) and optimizes intermediate adsorption via enhanced Co d-O p orbital hybridization.

Conclusions:

• Zirconium doping is an effective strategy to boost the performance of Co3O4 for acidic OER.
• The enhanced activity is attributed to the facilitation of the LOM pathway and optimized electronic structure.
• ZrxCo3-xO4 presents a promising non-precious metal alternative for PEMWE applications.