Intermediate Binding Control Using Metal-Organic Frameworks Enhances Electrochemical CO₂ Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Controlling intermediate binding is crucial for tuning product selectivity and activity in electrochemical CO2 reduction (CO2RR).
• Metal-organic frameworks (MOFs) offer a platform for encapsulating metal catalysts and tuning their local environment.

Purpose of the Study:

• To utilize reticular chemistry in MOFs to control CO2RR intermediate binding on encapsulated metal catalysts.
• To enhance CO2RR electrocatalysis by optimizing MOF properties like pore openness and Lewis acidity.

Main Methods:

• Systematic variation of organic linkers and metal nodes in face-centered cubic (fcc) MOFs.
• Encapsulation of silver (Ag) nanoparticles within the MOFs.
• Operando X-ray absorption spectroscopy (XAS) and in situ Raman spectroscopy for characterization under reaction conditions.

Main Results:

• MOFs demonstrated stability under operating conditions for CO2RR.
• Tuning MOF properties optimized the *CO binding mode on Ag nanoparticles.
• CO selectivity improved from 74% to 94% using a naphthalene dicarboxylic acid linker compared to a benzene dicarboxylic acid linker.

Conclusions:

• Reticular chemistry provides an effective strategy to design MOFs for enhanced CO2RR.
• MOF-encapsulated catalysts enable precise control over intermediate binding, leading to improved CO selectivity.
• This work presents a new materials design approach for CO2RR using MOFs.