Photocatalytic CO2 reduction with aminoanthraquinone organic dyes

Abstract

Summary

The photochemical reduction of CO₂ to CO was shown using the iron complex Fe(DHPP)Cl (100671) in combination with the aminoanthraquinone photosensitizers 1-aminoanthraquinone (100930), 1-amino-4-hydroxyanthraquinone (100931), 1-Amino-2-bromo-4-hydroxyanthraquinone (100932), Bromaminic acid (100933), 1,2-Diaminoanthraquinone (100958) and 1,4-Diaminoanthraquinone (100959). Turnover numbers (TONs) of up to 21616 and a selectivity of >99.9% for CO were reached in DMF after 48 h of irradiation. The experiments were conducted under visible-light irradiation (λ > 400 nm) with BIH (see section SEDs below) as sacrificial electron donor.

Advances and special progress

The authors present an efficient photocatalytic system with naturally abundant photosensitizers and without rare metals in which both the photosensitizer and catalyst show a high activity.

Additional remarks

For the most efficient system investigated in this study, a TON of 21616 per mole of catalyst and a TON of 6012 per mole of photosensitizer was obtained.

Content of the published article in detail

The article contains results of a study for the reduction of CO₂ to CO using an iron complex and different aminoanthraquinone-based photosensitizers. The catalytic system performs best (referring to the TON of CO production) in DMF with photosensitizer 1-Amino-2-bromo-4-hydroxyanthraquinone (100932).

Catalyst

Fe(DHPP)Cl (100671)

Photosensitizer

(100929) [Show R-Groups]

Investigation

		cat	cat conc [µM]	PS	PS conc [mM]	e-D	e-D conc [M]	solvent A	λexc [nm]	.	TON CO	.	.	.
(edit)	1.	Fe(DHPP)Cl	0.0006	Molecule:100930	0.02	BIH	0.06	DMF	>400		2395
(edit)	2.	Fe(DHPP)Cl	0.0006	Molecule:100958	0.02	BIH	0.06	DMF	>400		2738
(edit)	3.	Fe(DHPP)Cl	0.0006	Molecule:100959	0.02	BIH	0.06	DMF	>400		3551
(edit)	4.	Fe(DHPP)Cl	0.0006	Molecule:100931	0.02	BIH	0.06	DMF	>400		8360
(edit)	5.	Fe(DHPP)Cl	0.0006	Molecule:100932	0.02	BIH	0.06	DMF	>400		21616
(edit)	6.	Fe(DHPP)Cl	0.0006	Molecule:100933	0.02	BIH	0.06	DMF	>400		907

Experiment-Name: Photocatalytic reduction of CO2 with different photosensitizers

		cat	cat conc [µM]	PS	PS conc [mM]	e-D	e-D conc [M]	solvent A	λexc [nm]	TON CO	.	.
(edit)	1.	Fe(DHPP)Cl	0.0005	Molecule:100932	0.0005	BIH	0.06	DMF	> 400	3174
(edit)	2.	Fe(DHPP)Cl	0.001	Molecule:100932	0.001	BIH	0.06	DMF	> 400	3587
(edit)	3.	Fe(DHPP)Cl	0.002	Molecule:100932	0.002	BIH	0.06	DMF	> 400	3817
(edit)	4.	Fe(DHPP)Cl	0.005	Molecule:100932	0.005	BIH	0.06	DMF	> 400	4978
(edit)	5.	Fe(DHPP)Cl	0.01	Molecule:100932	0.01	BIH	0.06	DMF	> 400	4028
(edit)	6.	Fe(DHPP)Cl	0.0005	Molecule:100932	0.02	BIH	0.06	DMF	> 400	19158
(edit)	7.	Fe(DHPP)Cl	0.0006	Molecule:100932	0.02	BIH	0.06	DMF	> 400	21616
(edit)	8.	Fe(DHPP)Cl	0.001	Molecule:100932	0.02	BIH	0.06	DMF	> 400	17020
(edit)	9.	Fe(DHPP)Cl	0.002	Molecule:100932	0.02	BIH	0.06	DMF	> 400	11250
(edit)	10.	Fe(DHPP)Cl	0.01	Molecule:100932	0.02	BIH	0.06	DMF	> 400	3942
(edit)	11.	Fe(DHPP)Cl	0.02	Molecule:100932	0.02	BIH	0.06	DMF	> 400	2134
(edit)	12.	Fe(DHPP)Cl	0.05	Molecule:100932	0.02	BIH	0.06	DMF	> 400	891
(edit)	13.	Fe(DHPP)Cl	0.002	Molecule:100932	0.015	BIH	0.06	DMF	> 400	8772
(edit)	14.	Fe(DHPP)Cl	0.002	Molecule:100932	0.01	BIH	0.06	DMF	> 400	5593
(edit)	15.	Fe(DHPP)Cl	0.005	Molecule:100932	0.01	BIH	0.06	DMF	> 400	4128
(edit)	16.	Fe(DHPP)Cl	0.01	Molecule:100932	0.01	BIH	0.06	DMF	> 400	4028
(edit)	17.	Fe(DHPP)Cl	0.02	Molecule:100932	0.01	BIH	0.06	DMF	> 400	2325
(edit)	18.	Fe(DHPP)Cl	0.002	Molecule:100932	0.005	BIH	0.06	DMF	> 400	8780
(edit)	19.	Fe(DHPP)Cl	0.005	Molecule:100932	0.005	BIH	0.06	DMF	> 400	5258
(edit)	20.	Fe(DHPP)Cl	0.01	Molecule:100932	0.005	BIH	0.06	DMF	> 400	2576
(edit)	21.	Fe(DHPP)Cl	0.02	Molecule:100932	0.005	BIH	0.06	DMF	> 400	1539

Experiment-Name: Photocatalytic CO2 reduction with varying concentrations of cat and PS

Sacrificial electron donor

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

Additives

In this study, the addition of Hg(0) was tested.