This MOF uses light to capture and convert carbon dioxide

Converting carbon dioxide to fuels would be a way to reduce climate-changing emissions and our dependence on fossil fuels. It is possible today, but it requires multiple steps and a lot of heat.

Researchers have now made a metal-organic framework (MOF) that uses light to capture CO₂ and convert it to carbon monoxide (Chem 2026, DOI: 10.1016/j.chempr.2026.103073). Carbon monoxide is a valuable precursor for fuels and other chemicals. The MOF works on gas mixtures with 15% CO₂ concentrations typical of the exhaust from factories and power plants.

Carbon capture from flue gas today relies on sorbents that nab CO₂. Heating the sorbent releases the CO₂, which then needs to be concentrated and sent to a separate reactor for reduction. “This requires additional energy and equipment,” says Yunyang Qian, a chemist at the University of Science and Technology of China (USTC) and one of the study’s authors.

Aiming for a one-pot solution, Qian, Hai-Long Jiang of USTC, Bin Liu of City University of Hong Kong, and their colleagues combined the power of MOFs and photocatalysis.

MOFs are porous materials composed of metal ions connected with organic ligands. Using them to capture carbon isn’t new. Many teams are studying MOFs as adsorbents “because their pore size and chemical environment can be tailored to bind CO₂ selectively,” Qian says.

Meanwhile, photocatalysts, which absorb light and power chemical reactions, are attractive for converting CO₂ to useful chemicals. But these catalysts typically don’t work well at the low 3–20% concentrations of CO₂ found in flue gas.

Qian and his colleagues assembled MOFs from well-defined clusters of iron, manganese, and oxygen atoms connected with organic linkers. In addition to passively adsorbing CO₂, this MOF uses light to actively capture and transform the gas. Light drives electrons to the iron sites and promotes CO₂ capture by the Fe₂MnO cluster, Qian explains. The central oxygen atom and a neighboring iron site work together to convert CO₂ to a carbonate-like intermediate, which is then converted to CO.

The researchers dispersed the MOFs in an acetonitrile-based solution containing a ruthenium photosensitizer that absorbs light. They exposed the solution to a mixture of 15% CO₂ and 85% nitrogen and irradiated it with visible light at wavelengths above 420 nm. The material converted CO₂ to CO with 95% selectivity.

The system’s reliance on expensive ruthenium and organic solvents is a hindrance, says Julien Warnan, a photocatalysis expert at the Technical University of Munich. But this is still “a major conceptual advance,” and the material’s combination of CO₂ capture and conversion at the same catalytic site is impressive, he says.

Phillip Milner, an organic and materials chemist at Cornell University, finds the “unusual mechanism for light-driven capture . . . exciting.” The main challenge for CO₂ conversion technologies is that “flue gas streams are incredibly dirty,” he says. They contain contaminants such as nitrogen oxides, sulfur oxides, and oxygen, all of which can deactivate catalysts.

Qian and colleagues did indeed find that CO production plummeted in the presence of these contaminants. To make this lab-scale proof of concept practical, “our immediate priority is to improve tolerance to [flue gas impurities] and test the catalyst with real industrial flue gas,” he says. The researchers also aim to replace ruthenium and work on long-term stability.

But for now, the material’s performance at low CO₂ concentrations is still a notable advantage, Milner says. “The ability to directly convert a dilute stream of CO₂, consistent with emissions from a power plant, into a useful product helps to push the field forward.”