Oxygen evolution reaction: Bifunctional mechanism breaking the linear scaling relationship

Area of Science:

• Computational materials science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is crucial for many energy technologies.
• Linear scaling relationships often limit OER catalyst efficiency.
• A bifunctional mechanism offers a potential route to overcome these limitations.

Purpose of the Study:

• Investigate the bifunctional mechanism for OER using computational methods.
• Evaluate various catalyst materials under anodic conditions.
• Identify descriptors for optimal OER catalyst design.

Main Methods:

• Computational hydrogen electrode (CHE) method.
• Density Functional Theory (DFT) calculations at semilocal and hybrid functional levels.
• Modeling of anodic conditions to assess OER free energy steps.

Main Results:

• The bifunctional mechanism can overcome linear scaling limitations for specific catalysts.
• Smaller OER overpotentials are achievable by breaking scaling relationships.
• The highest occupied electronic state energy serves as a descriptor for hydrogen-accepting catalysts.

Conclusions:

• The bifunctional mechanism is a viable strategy to reduce OER overpotential.
• Catalyst design can be guided by the highest occupied electronic state energy.
• Computational screening aids in discovering efficient OER catalysts.