Mesoporous RE_0.5Ce_0.5O_2- Fluorite Electrocatalysts for the Oxygen Evolution Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for sustainable energy technologies like water electrolysis and CO2 reduction.
• Current OER catalysts often rely on expensive transition or noble metals, limiting their widespread application.
• Highly porous materials with high surface areas are desirable for improved catalytic performance.

Purpose of the Study:

• To synthesize highly porous fluorite nanocatalysts using evaporation-induced self-assembly (EISA).
• To investigate the effect of rare-earth cation substitution in CeO2 for enhanced OER activity and stability.
• To demonstrate a metal-free approach for developing high-performance OER electrocatalysts.

Main Methods:

• Evaporation-induced self-assembly (EISA) for synthesizing porous fluorite nanocatalysts.
• Rare-earth cation substitution (50% for Ce) in the CeO2 lattice.
• Electrochemical characterization of OER activity and stability in an alkaline medium.

Main Results:

• Rare-earth cation substitution introduces oxygen vacancies, decreasing OH* adsorption energy and enhancing OER activity.
• Nd2Ce2O7 exhibited the lowest OER overpotential (243 mV at 10 mA cm-2).
• The synthesized Nd2Ce2O7 demonstrated excellent cycling stability in alkaline conditions.

Conclusions:

• Rare-earth oxide nanocatalysts synthesized via EISA offer a promising alternative to traditional OER catalysts.
• The strategy of introducing oxygen vacancies through rare-earth substitution is effective for improving OER performance.
• This metal-free approach provides a pathway for cost-effective and sustainable OER electrocatalyst development.