A Permselective CeO_x Coating To Improve the Stability of Oxygen Evolution Electrocatalysts

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Nickel-iron oxide (NiFeO_x) electrocatalysts are highly active for the oxygen evolution reaction (OER).
• These catalysts deactivate over time due to the leaching of iron species from active sites into the electrolyte.
• This loss of active material limits their long-term performance and practical application.

Purpose of the Study:

• To develop a strategy to enhance the durability of NiFeO_x electrocatalysts for the OER.
• To investigate the protective effect of a cerium oxide (CeO_x) layer on catalyst stability.
• To understand the mechanism of protection and its impact on catalytic activity.

Main Methods:

• Anodic deposition of a cerium oxide (CeO_x) layer onto NiFeO_x electrocatalysts.
• Electrochemical testing to evaluate oxygen evolution reaction (OER) activity and stability.
• Analysis of the permselectivity of the CeO_x layer.

Main Results:

• The CeO_x layer effectively prevented the loss of Fe species from the NiFeO_x electrocatalyst during OER.
• The protected catalyst exhibited highly stable performance without compromising OER activity.
• The CeO_x layer demonstrated permselectivity, allowing OH^- and O₂ passage while blocking redox ion diffusion.

Conclusions:

• Anodic deposition of a CeO_x layer is a viable strategy to improve the durability of NiFeO_x electrocatalysts for OER.
• The permselective nature of the CeO_x layer is key to maintaining catalyst stability.
• This approach offers a new pathway for designing robust electrocatalysts for energy conversion applications.