Scientists have developed a new material that can use sunlight and water to convert carbon dioxide (CO2) into carbon monoxide (CO) – a key building block for making fuels, plastics, pharmaceuticals and other everyday chemicals.
The finding, led by The University of Manchester, could support the development of future technologies that recycle greenhouse gases to make fuels and useful chemicals, more sustainably, using nothing more than light and water.
CO2 is the main driver of human-caused climate change, but it is also an abundant carbon resource. Finding efficient ways to convert CO2 already in the atmosphere into useful products is a major scientific challenge.
The team’s new catalyst, published today in the Journal of the American Chemical Society, combines ideas from biology and materials science to address the problem.
Professor Martin Schröder, Professor of Chemistry at The University of Manchester, said: “In nature, specialised enzymes can bind and release small molecules like CO2 with remarkable control. We have been able to design a solid material that behaves in a similar way. It is activated by visible light to react and convert CO2 and the original material is then regenerated to react with more CO2”.
The work revolves around metal-organic frameworks (MOFs) - materials made from metal atoms or clusters connected by organic linkers to form porous networks of tiny cavities in which molecules can be adsorbed and activated for conversion to new products, in this case CO2 .
The researchers used a cerium-based MOF, built using organic linkers that contain amino groups to improve how it absorbs light. When illuminated, the material briefly undergoes an electronic change, creating temporary “open” sites in its pores that can grab hold of CO2 molecules. They then react and convert into CO before being released again.
This reversible binding behaviour is similar to how enzymes in living systems handle small molecules such as CO2.
In laboratory experiments, the new catalyst produces CO extremely efficiently, with no detectable by-products, outperforming many existing benchmark materials.
Unlike other existing systems, the process does not require precious metals or added chemicals that are consumed during the reaction. It also avoids producing large amounts of hydrogen instead of useful carbon-based products.
The new system uses only light, water and CO2, and produces one single valuable product.
Prof Sihai Yang, said: “Our research is still at a fundamental stage, but the findings provide a clear blueprint for designing next-generation catalysts that turn waste CO2 into useful chemicals.
“By learning from how nature controls chemical reactions, we can begin to design materials that open up exciting possibilities for clean and efficient energy technologies.”
The researchers believe the principles demonstrated here could be applied to a wide range of reactions, helping to accelerate the development of sustainable solar-to-fuel technologies.