Green plants accomplish the task of generating monomers and then polymers from CO₂ daily on a global scale. But what seems easy for plants remains a difficult problem for polymer scientists. Can we also find ways to make use of this inexpensive, relatively benign raw material to generate economically competitive synthetic polymers? Considered until recently as valueless due to its downcycling scenarios, plastic waste is now seriously perceived as a key carbon resource for future chemical technologies. Can the merging of both waste streams through combinatory chemistry lead our society on the path to sustainability and circularity? Those questions are of high importance … Over the last century, waste CO₂ (Nature 2019, 575, 87) and (micro)plastic contaminations (Nature 2021, 593, 22) have become the cancers of our planet, forcing humanity to embark on one of the biggest worldwide challenges: switching from our “use-and-make-waste” societal model to a new sustainable and circular paradigm. What’s more, with the extraction and transformation of raw chemicals in different parts of the world, our globalisation-based economic system has shown its limits. In this context, what if the problem became paradoxically the solution? The breakthrough in CO₂ catalysis has opened fantastic opportunities to fabricating commodities and sophisticated products (Nature Comm. 2015, 6, 5933).

CO₂, a main contributor to global warming, is the main carbon source on Earth, transformed into biomass by plants. Plastic waste, available everywhere, is also an underestimated carbon source. Why not consider the on-site exploitation of CO₂, biomass and plastic waste as the main locally available alternatives to fossil resources? CO₂ needs to be captured and transformed, and this is far from being science fiction, as biofuels, bioplastics and many fine organic chemicals are now accessible from this gas, with some products entering the market. Legislative changes and political, industrial and/or financial incentives are now the main drivers to surpass the huge costs associated with developing new catalytic solutions, maturing these emerging technologies and/or setting up new value chains, ideally by weaving synergies with other green initiatives including bio-resources and renewable energies.

By Olivier Coulembier, Christophe Detrembleur and Bruno Grignard