In the final stage of photosynthesis, plants convert carbon dioxide in the atmosphere into carbohydrates. A close collaboration of experimentalists and theorists from Brookhaven Lab and the Institute for Molecular Science in Japan have been trying to mimic that process with the goal of converting carbon dioxide into a clean, renewable fuel using sunlight.
The researchers submerged a light-absorbing ruthenium catalyst that mimics an important substance in photosynthesis in an aqueous solution containing an electron donor. When irradiated with visible light, the catalyst produces a renewable hydride donor that can transfer a negative ion of hydrogen to a hydride-acceptor molecule.
The researchers found that the catalyst was able to pool the energy from two photons — units of light energy — in the hydride donor. This catalyst is able to store two electrons generated by light and a proton as the hydride donor, which it can then transfer to an appropriate acceptor molecule. This process opens the door to light-induced, catalytic hydridetransfer reactions for transforming carbon dioxide to methanol.
D. E. Polyansky, D. Cabelli, J. T. Muckerman, T. Fukushima, K. Tanaka, E. Fujita, “Mechanism of Hydride Donor Generation Using a Ru(II) Complex Containing an NAD+ Model Ligand: Pulse and Steady-State Radiolysis Studies,” Inorg. Chem., 47 10 (2008).
Last Modified: November 04, 2009