2024-08-09 04:00:05
Artificial photosynthesis is a very promising biomimetic process that aims to convert carbon dioxide into carbon molecules of interest using solar energy. To be viable, this process must be simple and robust, inexpensive and selective. A major challenge that a team of Franco-Vietnamese scientists has just taken up thanks to a cobalt complex immobilized on materials of electrodes.
Although carbon dioxide (CO2) is the main gas responsible for climate change, it is also a source of carbone valuable for manufacturing the fuels, carbon materials and chemicals we will need in a post-oil society.
To achieve this, it is necessary to develop catalytic processes that can convert CO2 into molecules of interest while using renewable energy sources. These catalytic systems must be selective, both by producing only one CO2 conversion product, but also by avoiding the competitive production ofhydrogen via la decomposition water.
Researchers from the team SolHyCat at the Chemistry Laboratory and biology metals (CNRS/CEA/Université Grenoble Alpes) have shown that by immobilizing a cobalt coordination complex on carbon nanotubes, they obtained a material catalytic for the conversion of CO2 into carbon monoxide (CO) with more than 90% selectivity, the remaining 10% being hydrogen.
This system is fast and stable with more than 20,000 catalytic cycles performed in 2 hours without loss of activity. The resulting CO/H2 mixture, called synthesis gas (or syngas), is a key intermediate for the synthesis of a wide variety of products such as alcohols and hydrocarbons.
© Murielle Chavarot-Kerlidou
Even better, this same team, in collaboration with a group from the Franco-Vietnamese University of Hanoi, was able to integrate the cobalt-based catalyst into a photoelectrochemical cell. This cell uses thesolar energy to convert CO2 and water into synthesis gas in a completely autonomous.
At the heart of this device, the cobalt catalyst is combined with a photosensitizer to reproduce the functioning of photosynthetic living organisms.
Editor: AVR
References:
Impact of the Surface Microenvironment on the Redox Properties of a Co-Based Molecular Cathode for Selective Aqueous Electrochemical CO2-to-CO Reduction
Matthieu Haake, Dmitry Aldakov, Julien Pérard, Giulia Veronesi, Antonio Aguilar Tapia, Bertrand Reuillard & Vincent Artero.
J. Am. Chem. Soc. 2024
DOI: https://doi.org/10.1021/jacs.4c03089
Unassisted Solar Syngas Production by a Molecular Dye-Cobalt Catalyst Assembly in a Tandem Photoelectrochemical Cell
Duc N. Nguyen, Emmanouil Giannoudis, Tatiana Straistari, Jennifer Fize, Matthieu Koepf, Phong D. Tran, Murielle Chavarot-Kerlidou & Vincent Artero.
ACS Energy Letters 2024
DOI:
1723297566
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