Carbon emissions can be turned into clean fuels

A research team from the University of Cambridge in the UK and the Nova University Lisbon in Portugal has recently developed an efficient method to turn carbon dioxide into clean, sustainable fuels without any unwanted products or waste. The results demonstrate that polluting carbon emissions can be turned into clean fuels efficiently without any wasted energy.

Most methods for converting CO₂ into fuels also produce unwanted by-products such as hydrogen. Although chemical conditions can be altered in order to minimize the production of hydrogen, this process reduces the performance for CO₂ conversion. Thus, cleaner fuel can be produced, but only at the cost of efficiency. 

The newly developed proof of concept relies on enzymes isolated from bacteria to power electrolysis – the chemical reactions that convert CO₂ into fuel. While enzymes are more efficient than other catalysts, such as gold, they are highly sensitive to local chemical environments. 

By fine-tuning the solution conditions to alter the local environment of the enzymes, the researchers managed to improve fuel production efficiency by 18 times, compared to previous attempts. Moreover, adding an extra enzyme to control the environment, they sped up the reactions, both increasing efficiency and reducing unwanted by-products.

“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 first author of the Nature Chemistry paper Dr. Sam Cobb, an expert in Electrochemistry and Bioelectrocatalysis at the University of Cambridge. “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.”

“Once you manage to make better catalysts, many of the problems with CO₂ electrolysis just disappear. We’re showing the scientific community that once we can produce catalysts of the future, we’ll be able to do away with many of the compromises currently being made, since what we learn from enzymes can be transferred to synthetic catalysts,” he added.

Such processes will play a crucial role in reducing carbon emissions. Instead of capturing and storing carbon dioxide – a highly energy-intensive endeavor – electrolysis can capture carbon and transform it into something useful, in an energy-efficient way.

“In future we want to use what we have learned to tackle some challenging problems that the current state-of-the-art catalysts struggle with, such as using CO₂ straight from air as these are conditions where the properties of enzymes as ideal catalysts can really shine,” concluded Dr. Cobb.

The research is published in two related papers in Nature Chemistry and Proceedings of the National Academy of Sciences (PNAS).

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By Andrei Ionescu, Earth.com Staff Writer