Direct CO₂ Reduction to CO with an Fe₄S₄-Based Coordination Polymer

Area of Science:

• Inorganic Chemistry
• Electrochemistry
• Catalysis

Background:

• Iron-sulfur (Fe4S4) clusters are vital in biological electron transport and catalysis.
• Developing synthetic Fe4S4-based catalysts is crucial for advancing chemical transformations.
• Few synthetic Fe4S4 cluster-based catalysts have been reported.

Purpose of the Study:

• To utilize an Fe4S4-based coordination polymer as a catalyst for CO2 electroreduction.
• To investigate the mechanism of CO2 conversion to CO using computational and experimental methods.
• To establish Fe4S4 coordination polymers as effective electrocatalysts.

Main Methods:

• Computational studies (e.g., DFT) to model reaction pathways.
• Electrochemical characterization, including cyclic voltammetry (CV).
• In situ infrared (IR) spectroscopy to identify reaction intermediates.

Main Results:

• The Fe4S4 coordination polymer effectively catalyzes the direct and selective electroreduction of CO2 to CO.
• Computational studies suggest a mechanism involving CO2 binding, protonation, reduction, and water loss.
• Evidence for carbonyl-ligated Fe4S4 clusters was observed, indicating unusual small molecule binding.

Conclusions:

• Fe4S4 cluster-based coordination polymers are viable electrocatalysts for CO2 reduction.
• The study provides mechanistic insights into CO2 conversion mediated by these clusters.
• This work opens avenues for designing novel catalysts based on Fe4S4 coordination polymers.