Nature-inspired approach efficiently turns CO2 into clean fuel

Researchers believe they are now much closer to making synthetic catalysts offering more effective carbon dioxide electrolysis.  

A team at the University of Cambridge has conducted research leading to a major breakthrough in the effectiveness of converting CO2 into clean fuel – electrolysis – by focusing on environmental aspects. 

Previous work has shown that biological catalysts – enzymes – can produce fuels cleanly from carbon dioxide, but with low efficiency. Many methods also result in the production of excess gases, such as hydrogen, with steps taken to minimise this resulting in further reductions to efficiency. A further obstacle is found in the fact that enzymes collapse and reactions are slow if surrounding conditions are not exactly suited to the catalyst. 

A new study has now identified 18-fold improvements to efficiency by adjusting conditions to suit the enzyme, effectively tailoring the local environment to suit the specific compound. It is believed the investigation represents a significant step forward in the development of better synthetic catalysts, which currently lag well behind enzymes. 

‘Enzymes have evolved over millions of years to be extremely efficient and selective, and they’re great for fuel-production because there aren’t any unwanted by-products,’ said Dr Esther Edwardes Moore from Cambridge’s Yusuf Hamied Department of Chemistry, first author of the paper. ‘However, enzyme sensitivity throws up a different set of challenges. Our method accounts for this sensitivity, so that the local environment is adjusted to match the enzyme’s ideal working conditions.’

‘We ended up with just the fuel we wanted, with no side-products and only marginal energy losses, producing clean fuels at maximum efficiency,’ said Dr Sam Cobb, first author of the Nature Chemistry paper. ‘By taking our inspiration from biology, it will help us develop better synthetic catalyst systems, which is what we’ll need if we’re going to deploy CO₂ electrolysis at a large scale.’

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