🧪 What if we turned carbon monoxide into sugars?

Producing sugars without going through photosynthesis, their main production process on Earth?

Scientists have succeeded in directly converting carbon monoxide (CO) into complex carbohydrates - the fundamental building blocks of life - in an aqueous medium and in a single experimental reactor. These results, published in the journal Chemical Science, open an entirely new pathway for producing high-value-added molecules without resorting to biomass or enzymes.


Carbohydrates (or sugars) are currently mainly obtained from plant resources through complex biological processes. They are essential building blocks for many industrial and pharmaceutical processes. In the context of transitioning to alternatives to fossil resources, teams from the Paris Institute of Molecular Chemistry (CNRS/Sorbonne University) and the Coordination Chemistry Laboratory (CNRS, University of Toulouse) propose a new method to directly convert carbon monoxide (CO) into complex carbohydrates in water, without resorting to biomass or enzymes.

Until now, most CO transformation processes, which can themselves be obtained by reducing CO₂, only yielded simple compounds - methanol, short-chain hydrocarbons, or light alcohols. The formation of complex oxygenated molecules like carbohydrates remained out of reach without enzymes or biological systems.

Thanks to a two-step process combined in a single reactor, the scientists first performed an electrochemical reduction to transform CO into formaldehyde in the presence of a cobalt catalyst. They then polymerized this small organic molecule through a reaction called "formose" to form 5 or 6-carbon atom sugars like ribose or glucose, similar to those found in living organisms.

These two cascade reactions required meticulous optimization of experimental conditions: pH, temperature, nature of the electrolyte and catalysts used. This approach, entirely carried out in an aqueous medium, relies on the synergy between two molecular catalysts, an organometallic one (cobalt complex) and an organic one (carbene).

By successfully synthesizing formaldehyde in a controlled manner and then triggering its selective transformation into sugars, the team overcame a chemical barrier previously thought to be very difficult: the synthesis of multi-oxygenated molecules from a simple, abundant gas like CO without going through photosynthesis or using enzymes.

In the long run, these results published in the journal Chemical Science could enable the production of chemical intermediates or biomaterial precursors from recycled carbon, thus contributing to the transition towards a circular and decarbonized economy.