Monomers from CO2 : Superbases as Catalysts for Formate-to-Oxalate Coupling.

Invited for this month's cover are the Industrial Sustainable Chemistry group of Prof. Dr Gert-Jan M. Gruter and the Catalysis Engineering group of Dr. Raveendran Shiju at the University of Amsterdam. The image shows a full cycle from CO2 to polymers via several steps. The work reports the use of superbases in suitable environments to improve the formate coupling step by drastically lowering the reaction temperature and times whilst achieving higher yields. The Full Paper itself is available at 10.1002/cssc.202002725.

Monomers from CO2 : Superbases as Catalysts for Formate-to-Oxalate Coupling.

An interesting contribution to solving the climate crisis involves the use of CO2 as a feedstock for monomers to produce sustainable plastics. In the European Horizon 2020 project "OCEAN" a continuous multistep process from CO2 to oxalic acid and derivatives is developed, starting with the electrochemical reduction of CO2 to potassium formate. The subsequent formate-to-oxalate coupling is a reaction that has been studied and commercially used for over 150 years. With the introduction of superbases as catalysts under moisture-free conditions unprecedented improvements were shown for the formate coupling reaction. With isotopic labelling experiments the presence of carbonite as an intermediate was proven during the reaction, and with a unique operando set-up the kinetics were studied. Ultimately, the required reaction temperature could be dropped from 400 to below 200 °C, and the reaction time could be reduced from 10 to 1 min whilst achieving 99 % oxalate yield.