Water-Assisted Highly Efficient Photocatalytic Reduction of CO2 to CO with Noble Metal-Free Bis(terpyridine)iron(II) Complexes and an Organic Photosensitizer

Abstract

Summary

A photochemical reduction of CO₂ to CO was shown using the iron complexes 100947, 100948 and 100949 as catalysts in combination with the organic photosensitizer 4CzIPN. Turnover numbers (TONs) of 6320 and a selectivity of 99.4% for CO were reached in DMF/H₂O with catalyst 100949. The experiments were conducted under visible-light irradiation (λ = 440 nm) using TEA as sacrificial electron donor (see section SEDs below).

Advances and special progress

One of the highest TONs for CO₂ reduction with an organic thermally activated delayed fluorescence (TADF) compound as a photosensitizer was reported herein.

Additional remarks

The addition of water was found to strongly promote the catalytic reaction.

Content of the published article in detail

The article contains results for the reduction of CO₂ to CO under visible-light catalysis using the iron complex 100949 as a catalyst. The catalytic system performs best (referring to the TON of CO production) in DMF/H₂O.

Catalyst

100946 [Show R-Groups]

Photosensitizer

4CzIPN

Investigation

	cat	cat conc [µM]	PS	PS conc [mM]	e-D	e-D conc [M]	solvent A	.	.	.	λexc [nm]	.	TON CO	.	.
1.	Molecule:100949	0.01	4CzIPN	0.05	TEA	0.28	DMF				420-650		6320
2.	Molecule:100948	0.01	4CzIPN	0.05	TEA	0.28	DMF				420-650		2780
3.	Molecule:100947	0.01	4CzIPN	0.05	TEA	0.28	DMF				420-650		4500
4.	Molecule:100949	0.01	Ru(bpy)3	0.05	TEA	0.28	DMF				420-650		19
5.	Molecule:100949	0.01	4CzIPN	0.05	TEA	0.28	MeCN				420-650		992

Investigation-Name: photocatalytic CO2 conversionExport

Sacrificial electron donor

In this study, the experiments were done with the sacrificial electron donor TEA (TEA).

Additives

In this study, no additives were tested.