Quick and Easy Method to Dramatically Improve the Electrochemical CO2 Reduction Activity of an Iron Porphyrin Complex

The development of artificial molecular catalysts for CO2 reduction is the key to solving energy and environmental problems. Although chemical modifications can generally improve the catalytic activity of this class of compounds, they often require complicated synthetic procedures. Here, we report a simple procedure that dramatically enhances electrochemical CO2 reduction activity. A one-step counteranion-exchange reaction increased the solubility of a commercially available catalyst, iron(III) tetraphenylporphyrin chloride, in a variety of solvents, allowing the investigation of its catalytic performance under various conditions. Surprisingly, the turnover frequency for CO evolution in acetonitrile (MeCN) reached 7 300 000 s(-1), which is the highest among those of current best-in-class molecular catalysts. This excellent catalytic activity originates from the unique reaction between the generated Fe-I species and CO2 in MeCN during catalysis. The present study offers a quick and easy method for obtaining an efficient catalytic system for electrochemical CO2 reduction.

Automated summary

The development of artificial molecular catalysts for CO2 reduction is crucial in addressing energy and environmental challenges. A one-step counteranion-exchange reaction was found to significantly enhance the catalytic activity of a commercially available catalyst, resulting in the highest turnover frequency among current best-in-class molecular catalysts. This study offers a quick and easy method for obtaining an efficient catalytic system for electrochemical CO2 reduction.