Intermetallic Cobalt Indium Nanoparticles as Oxygen Evolution Reaction Precatalyst: A Non-Leaching p-Block Element

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Most transition-metal catalysts reconstruct into similar oxyhydroxides during the oxygen evolution reaction (OER).
• P-block elements typically leach out, limiting catalyst design.
• Indium's thermodynamic stability suggests it may behave differently under alkaline OER conditions.

Purpose of the Study:

• To investigate the structural behavior of transition metal indium phases during OER.
• To explore the potential of indium to remain in the solid phase and influence OER catalysis.
• To design tailored OER catalysts by leveraging indium's unique properties.

Main Methods:

• Synthesis of intermetallic cobalt indium (CoIn3) nanoparticles.
• In situ X-ray absorption spectroscopy.
• Scanning transmission electron microscopy.

Main Results:

• CoIn3 nanoparticles undergo phase segregation into cobalt oxyhydroxide and indium hydroxide.
• The resulting cobalt oxyhydroxide exhibits enhanced performance due to more accessible active sites compared to metallic-cobalt-derived catalysts.
• Indium remains on the electrode surface, forming interfaces with cobalt oxyhydroxide phases.

Conclusions:

• Indium exhibits distinct behavior compared to most p-block elements during OER.
• The stable interfaces formed by indium can be leveraged for systematic tuning of OER catalyst properties.
• This work opens new avenues for designing advanced electrocatalysts by utilizing indium's unique characteristics.