Stabilizing Polyoxometalate for Enhanced OER Performance Using a Porous Manganese Oxide Support

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for electrocatalytic water splitting but faces challenges due to high energy requirements and slow kinetics.
• Polyoxometalates (POMs) offer unique redox properties but suffer from poor stability in water, limiting their OER applications.
• Developing robust and efficient electrocatalysts is essential for advancing water splitting technologies.

Purpose of the Study:

• To enhance the performance and stability of polyoxometalates (POMs) for the oxygen evolution reaction (OER).
• To develop a novel electrocatalyst by anchoring POM nanosheets onto a conductive, carbon-protected manganese oxide support.
• To investigate the structural and electrochemical properties of the resulting nanohybrid material for efficient water splitting.

Main Methods:

• Anchoring keggin-type POM [TiCoW11O40]7- nanosheets onto carbon-protected manganese oxide (C-Mn2O3) nanospheres.
• Fabrication of the polyoxometalate/C-Mn2O3 (PCM) nanohybrid electrocatalyst.
• Electrochemical characterization of the PCM nanohybrid for OER activity and stability in 1 M KOH.

Main Results:

• The PCM nanohybrid exhibits enhanced POM/support contact, improving stability, reaction kinetics, and redox activity.
• Achieved a low overpotential of 300 mV at 10 mA cm−2 with a Tafel slope of 88 mV/dec.
• Demonstrated high mass activity (784 A/g at 1.6 V) and excellent stability over 100 hours at 100 mA cm−2.

Conclusions:

• The developed PCM nanohybrid presents a viable strategy for creating efficient and durable electrocatalysts for OER.
• Anchoring POMs onto a conductive support effectively addresses their solubility issues and enhances catalytic performance.
• This approach offers a low-cost material solution for advanced water splitting applications.