The researchers used the robust photocatalytic qualities of a ruthenium (Ru) dinuclear complex with self-photosensitizing capabilities to accomplish a highly effective CO2 reduction process in this study. This method produces an astonishingly high selectivity for carbon monoxide (CO).
It was found that the greatest quantum yield at 450 nm was 19.7%. Moreover, the photocatalytic CO2 reduction by the Ru complex proceeded with exceptional efficiency, demonstrating that nearly all of the introduced CO2 could be transformed into CO, even when the initial concentration of CO2 in the gas phase was lowered to 1.5%.
The two Ru complex moieties in this recently formed Ru dinuclear complex photosensitize, increasing the stability of the complex catalyst under reaction conditions. The ligand that was used has an incredibly potent chelating action, which is responsible for this increased stability.
To build a reaction system that can effectively drive the CO2 reduction process, even at a lower CO2 concentration equal to that of the Earth’s atmosphere, which is roughly 420 ppm, the researchers intend to improve the catalytic activity in the future.
This study was funded by a Grant-in-Aid for Transformative Research Areas (A) Green Catalysis Science for Renovating Transformation of Carbon-Based Resources (Green Catalysis Science) (JSPS KAKENHI grant no. JP23H04902) and Grants-in-Aid (nos. 21K18973 and 21H01947) from the Japan Society of Promotion of Science (JSPS, MEXT).
Journal Reference:
Ishizuka, T., et al. (2023) Self-Photosensitizing Dinuclear Ruthenium Catalyst for CO2 Reduction to CO. Journal of the American Chemical Society. doi:10.1021/jacs.3c07685