Research Aims to Use Sunlight to Turn Captured CO2 into Fuel

After a decades-long effort, an international study team is reporting “promising” first steps in using sunlight to convert captured carbon dioxide into fuel.

Led by Lund University in Sweden, researchers from Sweden, Denmark, Germany, China, and Russia, have successfully used a photocatalytic process to convert CO2 into carbon monoxide, reports Interesting Engineering.

Published in the journal Nature Communications, the announcement comes after 20 or more years of intense research into what is essentially a form of carbon capture. The researchers used a highly porous material called “covalent organic framework” (COF) to absorb sunlight very efficiently, then added a catalytic complex to trigger the conversion of CO2 to CO.

“The conversion to carbon monoxide requires two electrons,” Lund chemist researcher Zaibo Zheng explained in a release. “When we discovered that photons with blue light create long-lived electrons with high energy levels, we could simply charge COF with electrons and complete a reaction.”

Before the scientists can start thinking about a working CO2 converter, “many more steps need to be taken” and the initial work must be refined, Lund chemist Tönu Pullerits emphasized.

“But we have identified a very promising direction to take,” he added.

Citing a recent assessment by the U.S. Center for International Environmental Law, Interesting Engineering notes that carbon capture technologies are regarded by many as a “dangerous distraction” from the urgent need for a complete transition away from fossil fuels. The Lund University research team nonetheless “hope their process can be scaled up for use on a global level, making it one of the many solutions that will be required to overcome the climate crisis.” 

The breakthrough comes two years after researchers at Linköping University, also in Sweden, reported on their own efforts to perform what is essentially a kind of artificial photosynthesis.

Learning to convert CO2 to fuels like methane and ethane with the aid of solar energy “could contribute to the development of sources of renewable energy and reduce the impact on the climate of the combustion of fossil fuels,” said author Jianwu Sun, senior lecturer in the Department of Physics, Chemistry, and Biology at Linköping.

Photograph: ckirner