CeO₂ Functionalized Cobalt Layered Double Hydroxide for Efficient Catalytic Oxygen-Evolving Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Water splitting is crucial for hydrogen production to address the energy crisis.
• The oxygen-evolving reaction (OER) is a bottleneck in water splitting due to its high energy barrier.
• Layered double hydroxides (LDHs), particularly those modified with cerium dioxide (CeO₂), show promise for OER catalysis, but atomic-level mechanistic understanding is lacking.

Purpose of the Study:

• To investigate the atomic-level mechanism of enhanced OER catalytic performance in CeO₂-modified Co LDH.
• To optimize OER performance by anchoring CeO₂ nanoparticles onto Co LDH, focusing on loading capacity and size effects.
• To establish a correlation between site-specific electronic interactions and catalytic activity.

Main Methods:

• Anchoring CeO₂ nanoparticles onto Co LDH.
• Utilizing X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) to study electronic interactions.
• Employing in situ Raman spectroscopy to monitor reaction intermediates.

Main Results:

• Demonstrated electron transfer from Co²⁺ to Ce⁴⁺, increasing the concentration of Co³⁺.
• Identified enhanced binding of OH^- by Co³⁺ due to strong Lewis acidity, facilitating intermediate formation.
• Observed the formation of the key intermediate Co-OOH at a reduced potential via in situ Raman spectroscopy.

Conclusions:

• Anchoring CeO₂ nanoparticles onto Co LDH effectively enhances OER catalytic activity.
• Established a clear atomic-level correlation between interfacial electronic interactions and improved catalytic performance.
• Provides fundamental insights into designing efficient electrocatalysts for water splitting.