Photocatalytic CO2 Reduction Mediated by Electron Transfer via the Excited Triplet State of Zn(II) Porphyrin

Abstract

Summary

A photochemical reduction of CO₂ to CO was shown using the zinc porphyrin dyad with a connected rhenium complex (Zn(tBuPP))-(Re(Phen)Br(CO)3) (100954) as a combined catalyst and photosensitizer molecule. Turnover numbers (TONs) of >1300 and a selectivity of >99.9% for CO were reached in DMA. The experiments were conducted under visible-light irradiation (λ = 420 nm) using BIH as sacrificial electron donor (see section SEDs below).

Advances and special progress

A selective method for the reduction of CO₂ to CO with a porphyrin-rhenium complex dyad was presented, effectively linking the catalyst and photosensitizer in one molecule.

Content of the published article in detail

The article contains results for the reduction of CO₂ to CO under visible-light catalysis using (Zn(tBuPP))-(Re(Phen)Br(CO)3) (100954) as a catalyst and photosensitizer. The catalytic system performs best (referring to the TON of CO production) in DMA.

Catalyst and Photosensitizer

(Zn(tBuPP))-(Re(Phen)Br(CO)3) (100954)

Investigation

		cat	cat conc [µM]	e-D	e-D conc [M]	solvent A	additives	.	.	λexc [nm]	.	TON CO	.	.	.	.	.
(edit)	1.	(Zn(tBuPP))-(Re(Phen)Br(CO)3)	0.05	BIH	0.05	DMA	phenol			420 nm		910
(edit)	2.	(Zn(tBuPP))-(Re(Phen)Br(CO)3)	0.075	BIH	0.05	DMA	phenol			420 nm		1340
(edit)	3.	(Zn(tBuPP))-(Re(Phen)Br(CO)3)	0.05	BIH	0.05	DMA				420 nm		520

Investigation-Name: photocatalytic CO2 conversion

Sacrificial electron donor

In this study, the experiments were done with the sacrificial electron donor BIH BIH (100508).

Additives

In this study, phenol was used as an additive.