Platinum-Decorated Ceria Enhances CO₂ Electroreduction in Solid Oxide Electrolysis Cells.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Solid oxide electrolysis cells (SOECs) offer a pathway for CO2 electroreduction, converting greenhouse gases into chemical energy.
• The cathode material's ability to adsorb and activate CO2 is critical for SOEC efficiency.
• La0.6Sr0.4Co0.2Fe0.8O3-δ -Ce0.8Sm0.2O2-δ (LSCF-SDC) is a potential SOEC cathode, but its catalytic activity requires improvement.

Purpose of the Study:

• To enhance the electrocatalytic activity of LSCF-SDC cathodes for CO2 electroreduction in SOECs.
• To investigate the effect of constructing Pt/SDC interfaces on SOEC performance.
• To understand the mechanism behind the performance improvement.

Main Methods:

• Decoration of platinum (Pt) nanoparticles onto the SDC surface to create Pt/SDC interfaces.
• Electrochemical measurements to assess SOEC performance, including polarization resistance and current density.
• Physicochemical characterizations to analyze the cathode's properties, such as oxygen vacancy concentration and CO2 adsorption.

Main Results:

• The polarization resistance of the SOEC with Pt/SDC interfaces decreased significantly from 0.308 to 0.120 Ω·cm².
• The current density improved from 0.913 to 1.420 A·cm⁻² at 1.6 V and 800 °C.
• Pt/SDC interface construction led to increased oxygen vacancy concentration and enhanced CO2 adsorption and dissociation.

Conclusions:

• The Pt/SDC interfaces effectively improve the electrocatalytic activity of SOEC cathodes for CO2 electroreduction.
• The enhanced performance is attributed to increased oxygen vacancies and improved CO2 adsorption and dissociation kinetics at the cathode.
• This study demonstrates a viable strategy for optimizing SOEC cathodes for efficient CO2 utilization.