Photocatalytic Reduction of CO2 by Highly Efficient Homogeneous FeII Catalyst based on 2,6-Bis(1’,2’,3’-triazolyl-methyl)pyridine. Comparison with Analogues.

Abstract

Summary

A photochemical reduction of CO₂ to CO was shown using the iron complex (100941) as catalyst in combination with the copper photosensitizer (100940). Turnover numbers (TONs) of 576 and a selectivity of 67% for CO were reached in MeCN/TEOA. The experiments were conducted under visible-light irradiation (λ = 420 nm) using BIH as sacrificial electron donor (see section SEDs below). The homoleptic iron complex (100942) and the cobalt complexes (100944) and (100945) were tested for CO₂ reduction as well, but did not show substantial conversion of CO₂ to CO.

Advances and special progress

The authors reported a iron complex with one of the highest activities for CO₂ reduction among earth-abundant systems with monometallic iron catalysts.

Additional remarks

In addition to the production of CO, a substantial amount of H₂ (TON of 287) was formed in the reduction process with complex (100941).

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 (100941) as a catalyst. The catalytic system performs best (referring to the TON of CO production) in MeCN/TEOA.

Catalyst

(100941) (100942) (100944) (100945)

Photosensitizer

(100940)

Investigation

		cat	cat conc [µM]	PS	PS conc [mM]	e-D	e-D conc [M]	solvent A	.	.	additives	.	.	λexc [nm]	.	TON CO	TON CH4	TON H2	.	.
(edit)	1.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						420		107		43
(edit)	2.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						420		109		54
(edit)	3.	Molecule:100941	0.03	Molecule:100940	0.33	BIH	0.00666	MeCN						420		238		137
(edit)	4.	Molecule:100941	0.03	Molecule:100940	1.0	BIH	0.02	MeCN						420		314		151
(edit)	5.	Molecule:100941	0.01	Molecule:100940	1.0	BIH	0.02	MeCN						420		576		287
(edit)	6.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.1	MeCN						420		80		33
(edit)	7.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.1	MeCN			water			420		7.4		6.4
(edit)	8.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						420		3.2		1.6
(edit)	9.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						420		80		34
(edit)	10.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						420		100		43
(edit)	11.			Molecule:100940	1.0	BIH	0.02	MeCN						420		0		1
(edit)	12.	Molecule:100941	0.1			BIH	0.02	MeCN						420		0		0
(edit)	13.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN								0		0
(edit)	14.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						420		0		0
(edit)	15.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN			Hg			420		93		50
(edit)	16.	Molecule:100941	0.1	Molecule:100940	1.0	BIH	0.02	MeCN						solar simulator		450		348
(edit)	17.	Molecule:100941	0.01	Molecule:100940	1.0			MeCN						420		6.8	0	0
(edit)	18.	Molecule:100941	0.01	Molecule:100940	1.0	BIH	0.02	MeCN						420		44	1.16	0
(edit)	19.	Molecule:100941	0.01	Molecule:100940	1.0			MeCN						420		0	0	0
(edit)	20.	Molecule:100941	0.01	Molecule:100940	1.0	BIH	0.02	MeCN						420		0	0	0

Investigation-Name: Optimization of CO2 reduction conditionsREDIRECT Optimization of CO2 reduction conditionsInvestigation-Name: CO2 reduction experiments with different catalysts

Sacrificial electron donor

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

Additives

In this study, control experiments with Hg and without CO₂ were conducted.