Directional Ion Migration Enables Precise Heterointerface Optimization for High-Temperature CO₂ Electrolysis.

Area of Science:

• Materials Science and Engineering
• Electrochemistry
• Catalysis

Background:

• Heterointerfaces in composite electrodes are crucial for catalytic performance but difficult to optimize.
• Solid oxide electrolysis cells (SOECs) require efficient electrodes for CO2 electrolysis.

Purpose of the Study:

• To develop a novel ion-directional migration strategy for precise optimization of heterointerfaces in SOEC composite electrodes.
• To enhance the catalytic activity and efficiency of CO2 electrolysis.

Main Methods:

• Designed a composite electrode (SFM-005Ru@CeO2) using Sr2Fe1.5Mo0.5O6-δ perovskite and Ru0.05Ce0.95O2 fluorite.
• Utilized thermal treatment to induce directed migration of Ru ions to perovskite-fluorite heterointerfaces.
• Fabricated a solid oxide electrolysis cell with LSGM electrolyte and the optimized composite cathode.

Main Results:

• Achieved precise optimization of heterointerfaces, enhancing oxygen vacancy concentration and electronic environment.
• The optimized SFM-005Ru@CeO2 cathode delivered an ultrahigh current density of 3.80 A cm⁻² at 1.5 V for CO2 electrolysis at 800 °C.
• Demonstrated excellent stability, maintaining performance over 200 hours under harsh conditions.

Conclusions:

• The ion-directional migration strategy effectively optimizes heterointerfaces in composite electrodes for SOECs.
• This approach significantly enhances CO2 electrolysis performance, surpassing existing electrode materials.
• Opens new avenues for composite material improvement through precise heterointerface engineering in catalysis.