Modulation of IrO₆ Chemical Environment for Highly Efficient Oxygen Evolution in Acid

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Sluggish oxygen evolution reaction (OER) kinetics hinder the commercialization of oxygen electrochemistry.
• OER is crucial for renewable energy technologies like fuel cells and electrolyzers.

Purpose of the Study:

• To develop a facile strategy for incorporating single iridium (Ir) atoms into transition metal oxides (TMOs).
• To enhance OER activity and durability by stabilizing single Ir atoms within the TMO lattice.

Main Methods:

• Incorporation of Ir single atoms into TMO lattice.
• Modulation of the chemical environment of Ir and neighboring lattice oxygen.
• Characterization of catalyst performance for OER and overall water splitting.

Main Results:

• Ir single atoms stabilized by lattice oxygen, enhancing OER activity and durability.
• Ir_0.08Co_2.92O₄ nanowires achieved mass activity of 1343.1 A g^-1 and TOF of 0.04 s^-1 at 300 mV overpotential.
• Demonstrated excellent stability (100 h at 10 mA cm^-2) and efficient overall water splitting (1.494 V at 10 mA cm^-2).

Conclusions:

• A simple approach to create highly active and acid-stable TMO electrocatalysts with trace Ir.
• The developed catalyst shows great promise for applications in fuel cells and electrolyzers.
• Stabilizing single atoms in TMOs is an effective strategy for improving electrocatalytic performance.