High-performance NiOOH/FeOOH electrode for OER catalysis

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Oxygen evolution reaction (OER) catalysts are crucial for energy conversion technologies.
• Existing catalysts face limitations due to linear scaling relationships between intermediates.
• NiOOH/FeOOH systems show promise but require mechanistic understanding.

Purpose of the Study:

• To investigate the bifunctional mechanism of NiOOH/FeOOH catalysts for OER.
• To explore how distinct active sites in NiOOH/FeOOH can overcome scaling limitations.
• To computationally assess various interfaces of FeOOH and NiOOH for OER.

Main Methods:

• Computational Hydrogen Electrode (CHE) method.
• Modeling of FeOOH catalyst and NiOOH hydrogen acceptor.
• Evaluation of different interfacial configurations of NiOOH/FeOOH.

Main Results:

• A bifunctional mechanism involving adsorbed O2 on FeOOH and adsorbed H on NiOOH was identified.
• This mechanism effectively replaces the unfavorable OOHads intermediate.
• Calculations predicted low overpotentials as low as 0.16 V for optimized interfaces.

Conclusions:

• The bifunctional mechanism is key to the high performance of NiOOH/FeOOH OER catalysts.
• This strategy successfully circumvents the detrimental effects of linear scaling relationships.
• Optimized interfaces of NiOOH/FeOOH offer a promising pathway for efficient OER catalysis.