Research Results
Sep 3, 2018
- Press Release
- Research Paper
A press release on the research results of Prof. Yutaka Amao's group has been issued
Succeeded in developing a new artificial photosynthesis technology that can bind carbon dioxide to organic molecules and fix them
A group led by Professor Yutaka Amao (Research Center for Artificial Photosynthesis, Osaka City University) and Takeyuki Katagiri (2nd year doctoral student, Department of Materials and Molecular Science, Graduate School of Science) has succeeded in developing a new artificial photosynthesis technology that can bind carbon dioxide to organic molecules and fix them using visible light energy. The results of this research were published in Pure and Applied Chemistry, published by the International Union of Pure and Applied Chemistry (IUPAC) on September 3, 2018.
Research Summary
Most conventional artificial photosynthesis technologies photoreduce carbon dioxide to carbon monoxide, formic acid, formaldehyde, and methanol. In these systems, carbon dioxide with a carbon atom of 1 is reduced, so only molecules with a carbon number of 1 are produced (Fig. 1). On the other hand, in natural photosynthesis, the reducing power produced by solar energy is used to reduce carbon dioxide, expand the number of carbons, and finally produce glucose with 6 carbon atoms. If the number of carbons can be expanded in the same way as natural photosynthesis, new developments in the synthesis of various materials using carbon dioxide as raw materials can be expected.
Figure 1: Overview of conventional artificial photosynthesis
In this research, we developed a technology that can introduce carbon dioxide as a carboxy group (malic acid) into an organic molecule (pyruvate) based on the reducing power obtained by visible light energy using dye molecules, electron transfer molecules, and biocatalysts using the carbon expansion reaction of a natural photosynthetic reaction (Fig. 2)
Figure 2: New Artificial Photosynthesis (Results of this study)
The newly developed reaction system is a combination of a malic acid enzyme, which catalyzes a reaction in which carbon dioxide is bonded to pyruvate with 3 carbon atoms and converted to malic acid with 4 carbon atoms, and a photoreduction system of a newly developed diphenylbiologne derivative.
Until now, malic acid production systems from carbon dioxide and pyruvate using visible light energy using malic acid enzymes as catalysts have required the use of very complex and expensive reagents as shown in the figure below. In particular, the reaction elements enclosed in the dotted line in the figure below are very expensive and inefficient, which has been a barrier to research so far.
By using diphenylbiologen derivatives, we succeeded for the first time in the world in simplifying the dotted area in the figure. As a result, we have succeeded in constructing a new artificial photosynthesis system that can add carbon dioxide to pyruvate. Specifically, in a reaction system that uses water-soluble porphyrin as a dye and links a diphenylbiologen derivative with a malic acid enzyme, approximately 5% of the raw material pyruvate and carbon dioxide can be converted to malic acid by 3 hours of visible light irradiation. It can be said that we have achieved a new artificial photosynthesis system that can use carbon dioxide as a raw material, as opposed to an artificial photosynthesis system that has been mainly based on the reduction of carbon dioxide until now.
Future Developments
The result of this research is a system that can be applied to the recycling of carbon dioxide and the synthesis of various organic molecules by utilizing the function of biocatalysts using solar energy as a driving force. In recent years, research has been conducted on the composite of biocatalysts with semiconductor photocatalysts and organic inorganic materials. Since enzymes that catalyze carbon dioxide recycling reactions have the advantage of high reaction product selectivity, we would like to develop a new artificial photosynthesis system in the future not only for the conversion of carbon dioxide into fuel, but also for the synthesis of various chemical products and useful substances by binding carbon dioxide to organic molecules.
Addendum
This research was awarded the RSC Green Chemistry Poster Prize at the 7th International IUPAC Conference on Green Chemistry held in Moscow, Russia in October 2017.
IUPAC was founded in 1919 and is recognized as the world's leading authority on the naming standard for elements and compounds (IUPAC nomenclature).
(RSC：Royal Society of Chemistry)
Publication Information
| Publications: | Pure and Applied Chemistry (International Union of Pure and Applied Chemistry IUPAC) |
|---|---|
| Title of Paper: | Visible Light-induced Reduction System of Diphenylviologen Derivative with Water-soluble Porphyrin for Biocatalytic Carbon-carbon Bond Formation from CO2 |
| Author: | Takayuki Katagiri, Kohei Fujita, Shusaku Ikeyama, Yutaka Amao |
| URL: | https://www.degruyter.com/view/j/pac.ahead-of-print/pac-2018-0402/pac-2018-0402.xml |
Article source: Osaka City University website