Dinuclear ruthenium complex as a photocatalyst that selectively reduces CO2 to CO

Similar to the photosynthetic process in plants, the conversion and storage of solar energy into chemical energy holds great promise in addressing important energy and environmental challenges, such as fossil fuel depletion and the threat of global warming. . One promising avenue in this pursuit is the use of light energy to convert CO.₂ For value-added chemicals.

in recent researchResearchers at the University of Tsukuba have exploited the strong photocatalytic properties of a ruthenium (Ru) dinuclear complex with self-photosensitizing ability to achieve surprisingly efficient CO2 production.₂ reduction reaction. This process provides high selectivity for carbon monoxide (CO). Their research is Journal of the American Chemical Society.

For dimethylacetamide/H₂An O mixture containing a Ru dinuclear complex as a photocatalyst and a sacrificial reducing agent was exposed to light with a center wavelength of 450 nm in 1 atm of CO.₂ After 10 hours in the atmosphere, all the sacrificial reductant is consumed and the substrate CO₂ Converted to CO with >99% selectivity.

The maximum quantum yield at 450 nm was determined to be 19.7%. Furthermore, even in the case of initial CO;₂ The concentration in the gas phase decreased to 1.5%, and the photocatalytic CO₂ Reduction by the Ru complex proceeded with remarkable efficiency, indicating that almost all of the introduced CO was reduced.₂ Can be converted to CO.

In this newly developed Ru dinuclear complex, two Ru complex moieties participate in photosensitization, which improves the stability of the complex catalyst under reaction conditions. This increased stability may be due to the very strong chelating effect of the used ligand.

In the future, the researchers plan to further enhance the catalytic activity and build a reaction system that can efficiently emit CO.₂ Reduction process even with lower CO₂ This corresponds to the concentration in Earth’s atmosphere, approximately 420 ppm.