Oxygen deficient layered double perovskite as an active cathode for CO2 electrolysis using a solid oxide conductor

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Carbon dioxide (CO2) electrolysis is crucial for sustainable energy.
• Developing efficient cathode materials is key to improving CO2 electrolysis performance.
• Layered perovskites offer potential due to their unique structural and electronic properties.

Purpose of the Study:

• To investigate A-site ordered PrBaMn2O(5+δ) as a cathode for CO2 electrolysis.
• To evaluate the electrocatalytic activity and electrochemical properties of PrBaMn2O(5+δ).
• To assess the performance of PrBaMn2O(5+δ) with a La(0.9)Sr(0.1)Ga(0.8)Mg(0.2)O3 (LSGM) electrolyte.

Main Methods:

• Synthesis and characterization of A-site ordered PrBaMn2O(5+δ).
• Electrochemical testing of PrBaMn2O(5+δ) as a cathode in a CO2 electrolysis cell with an LSGM electrolyte.
• Impedance spectroscopy to evaluate electrochemical properties.

Main Results:

• PrBaMn2O(5+δ) demonstrated enhanced electrocatalytic activity for CO2 reduction.
• The material supports mixed valent manganese cations, promoting high electrical conductivity and oxygen vacancy content.
• A reversible oxygen switchover was observed during oxidation from the O5 to O6 phase.
• Successful CO2 electrolysis was achieved, with the cathode exhibiting a current density of 0.85 A cm⁻² at 1.5 V and 850 °C.

Conclusions:

• A-site ordered PrBaMn2O(5+δ) is a promising cathode material for CO2 electrolysis.
• Its layered perovskite structure and mixed valency contribute to efficient electrocatalysis and ion diffusion.
• The material shows excellent performance and electrochemical stability in conjunction with an LSGM electrolyte.