Oxygen Evolution Catalysis with Mössbauerite-A Trivalent Iron-Only Layered Double Hydroxide

Area of Science:

• Materials Science
• Electrochemistry
• Inorganic Chemistry

Background:

• Layered double hydroxides (LDHs) are crucial for catalysis.
• Iron-based LDHs are sought-after due to earth abundance.
• Mössbauerite, an Fe-only mineral, has not been explored for oxygen evolution.

Purpose of the Study:

• To investigate Mössbauerite as an electrocatalyst for the oxygen evolution reaction (OER).
• To synthesize and characterize Mössbauerite for OER applications.
• To evaluate the performance and stability of iron-only LDHs in alkaline media.

Main Methods:

• Synthesis of Mössbauerite via green rust intermediate.
• Electrocatalytic testing of Mössbauerite on a glassy carbon electrode.
• Electrochemical characterization including stability measurements and post-electrolysis analysis.

Main Results:

• Mössbauerite catalyzes the oxygen evolution reaction with a current density of 10 mA cm⁻² at 1.63 V vs. RHE.
• The synthesis conserves the layered double hydroxide structure.
• Stability and post-electrolysis characterization data are presented.

Conclusions:

• Iron-only layered double hydroxides, exemplified by Mössbauerite, are applicable as earth-abundant OER electrocatalysts.
• Mössbauerite's all Fe³⁺ composition allows for intrinsic performance evaluation, free from synergistic effects.
• This research opens avenues for sustainable and cost-effective OER catalysts.