The Spin Modulation Stimulated Efficient Electrocatalytic Oxygen Evolution Reaction over LaCoO₃ Perovskite

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Perovskite materials are investigated as non-noble catalysts for the oxygen evolution reaction (OER).
• Enhancing the catalytic performance of perovskites remains a challenge.
• Developing efficient OER catalysts is crucial for energy conversion technologies.

Purpose of the Study:

• To propose and investigate a spin state modulation strategy for improving the OER electrocatalytic activity of LaCoO3 perovskite.
• To understand the relationship between electronic configuration and catalytic performance.

Main Methods:

• High-temperature thermal reduction to induce electronic configuration transitions in LaCoO3.
• Mössbauer spectroscopy (M-H hysteresis loop) to analyze spin state changes and electron spin polarization.
• Electrochemical measurements to evaluate OER activity and overpotential.

Main Results:

• Thermal reduction promoted electron transitions from low spin to high spin states in Co, increasing spin polarization.
• Optimized LaCoO3 exhibited significantly reduced OER overpotential (396 mV at 10 mA cm⁻²) compared to the original state.
• An external magnetic field further improved OER efficiency (383 mV overpotential) due to optimized electron filling.

Conclusions:

• Spin state modulation is an effective strategy to boost the OER electrocatalytic activity of perovskites.
• Tailoring the electronic configuration of LaCoO3 enhances its performance as an OER catalyst.
• This approach offers a new pathway for designing advanced electrocatalysts.