p-p Orbital Hybridization Stabilizing Lattice Oxygen in Two-Dimensional Amorphous RuO_x for Efficient Acidic Oxygen...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient and stable electrocatalysts for the acidic oxygen evolution reaction (OER) is critical for energy applications.
• Ruthenium-based (Ru) catalysts are promising alternatives to iridium but suffer from poor stability due to reactive lattice oxygen.

Purpose of the Study:

• To stabilize lattice oxygen in 2D amorphous RuO_x via p-p orbital hybridization using dopants.
• To enhance the catalytic activity and durability of Ru-based catalysts for acidic OER.

Main Methods:

• Incorporation of dopants (Al, Ga, In) into 2D amorphous RuO_x to induce p-p orbital hybridization.
• Electrochemical testing to evaluate catalytic performance (overpotential, stability).
• In situ electrochemical spectroscopic analysis and theoretical calculations to elucidate the mechanism.

Main Results:

• Gallium (Ga) doping significantly improved acidic OER performance, reducing overpotential by 137 mV and increasing stability 125-fold compared to undoped RuO_x.
• Ga doping suppressed Ru overoxidation and shifted the reaction mechanism.
• Doping with other elements (Mn, Co, Cu) showed minimal improvement.

Conclusions:

• P-p orbital hybridization is an effective strategy to stabilize lattice oxygen in RuO_x catalysts.
• Ga-doped RuO_x demonstrates superior activity and stability for acidic OER, surpassing most reported Ru-based catalysts.
• This approach offers a pathway for developing robust electrocatalysts for OER and other energy conversion reactions.