Atomic Manipulation to Create High-Valent Fe⁴⁺ for Efficient and Ultrastable Oxygen Evolution at Industrial-Level...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Improving catalyst performance via atomic-level electronic structure manipulation is challenging.
• The oxygen evolution reaction (OER) is crucial for water splitting but requires efficient catalysts.

Purpose of the Study:

• To develop a novel catalyst with enhanced OER activity and stability.
• To investigate the mechanism of improved catalytic performance through atomic structure modification.

Main Methods:

• Atomic-level insertion of Mo into FeOOH to create Fe-O-Mo units.
• In situ X-ray absorption spectroscopy to reveal high-valent Fe4+ species.
• Electrochemical testing of the Fe-Mo-Ni3S2 catalyst for OER and overall water splitting.

Main Results:

• The Fe-Mo-Ni3S2 catalyst achieved an industrial-level current density of 1 A cm-2 at a low overpotential of 259 mV (at 60 °C).
• The catalyst demonstrated outstanding stability, operating for over 2000 hours at high current densities.
• The Fe-Mo-Ni3S2||Pt/C system achieved 1 A cm-2 for overall water splitting at 1.68 V, outperforming RuO2||Pt/C.

Conclusions:

• Atomic manipulation creating Fe-O-Mo units and high-valent Fe4+ significantly enhances OER activity and stability.
• The developed Fe-Mo-Ni3S2 catalyst offers a promising low-cost, efficient, and ultrastable solution for practical water splitting applications.