Exchange Coupling Determines Metal-Dependent Efficiency for Iron- and Cobalt-Catalyzed Photochemical CO2 Reduction

Abstract

Summary

A photochemical reduction of CO2 to CO was shown using an Fe2+ and Co2+ complexes as catalysts in combination with Ruxx as photosensitizer.

metal−ligand exchange coupling as an example of charge delocalization that can determine the efficiency for photocatalytic CO2RR. A comparative evaluation of iron and cobalt complexes supported by the redox-active ligand tpyPY2Me establishes that the two-electron reduction of [Co(tpyPY2Me)]2+ ([Co]2+) occurs at potentials 770 mV more negative than the [Fe(tpyPY2Me)]2+ ([Fe]2+) analogue by maximizing the exchange coupling in the latter compound.

Catalysts tested in this study

(100968) (100969)

Photosensitizer

Ru(bpy)3 (100680) 3,6-Diamino-10-methylacridinium (100970) (100971) Ir(ppy)3 (100843)

Investigation

		cat	cat conc [µM]	PS	PS conc [mM]	e-D	e-D conc [M]	.	.	solvent A	additives	.	.	TON CO	TON H2	.	.	.
(edit)	1.	Molecule:100968	2	Ru(bpy)3	0.2	BIH	0.1			MeCN				15520	86
(edit)	2.	Molecule:100968	0.2	Ru(bpy)3	0.2	BIH	0.1			MeCN				30349	1013
(edit)	3.			Ru(bpy)3	0.2	BIH	0.1			MeCN				43	52
(edit)	4.	Molecule:100968	2			BIH	0.1			MeCN				112	0
(edit)	5.	Molecule:100968	2	Ru(bpy)3	0.2					MeCN				150	0
(edit)	6.	Molecule:100968	2	Ru(bpy)3	0.2	BIH	0.1			MeCN				6	0
(edit)	7.	Molecule:100968	2	Ru(bpy)3	0.2	BIH	0.1			MeCN	Ar			0	222
(edit)	8.	Molecule:100968	2	Molecule:100971	0.2	BIH	0.1			MeCN				12749	163
(edit)	9.	Molecule:100968	0.2	Molecule:100971	0.2	BIH	0.1			MeCN				28712	6527
(edit)	10.	Molecule:100968	2	Ir(ppy)3	0.2	BIH	0.1			MeCN				18502	141
(edit)	11.	Molecule:100968	2	Molecule:100970	0.2	BIH	0.1			MeCN				6710	0

Experiment-Name: Iron-Catalyzed Photochemical CO2 Reduction under diverse conditions_error

Further Information

The Supporting Information gives quantum yields for described experiments in Table 1.

Sacrificial electron donor

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

Tags

TagContains tags that describe the content of the page.: photocatalytic CO2 reduction (Ontology: voc4cat, OBOID: voc4cat:0000099), TagContains tags that describe the content of the page.: CO