A local proton source enhances CO2 electroreduction to CO by a molecular Fe catalyst

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrochemical conversion of carbon dioxide (CO(2)) to carbon monoxide (CO) is crucial for producing fuels and chemicals.
• Iron tetraphenylporphyrin is a known catalyst for this transformation.

Purpose of the Study:

• To enhance the catalytic activity and stability of iron tetraphenylporphyrin for CO(2) to CO conversion.
• To investigate the role of phenolic group modification on catalyst performance.

Main Methods:

• Modification of iron tetraphenylporphyrin by introducing phenolic groups.
• Electrochemical catalysis experiments to measure CO faradaic yield and turnover number.
• Analysis of catalyst stability and overpotential requirements.

Main Results:

• The modified catalyst achieved a CO faradaic yield above 90%.
• The catalyst demonstrated over 50 million turnovers in 4 hours with no degradation.
• The reaction proceeded at a low overpotential of 0.465 V.

Conclusions:

• Phenolic group modification significantly accelerates the electrochemical CO(2) to CO conversion.
• The enhanced activity is attributed to the local proton concentration from phenolic hydroxyl groups.
• This earth-abundant catalyst offers a stable and efficient route for CO(2) valorization.