Researchers from the Oregon State University College of Science have demonstrated the potential of an inexpensive nanomaterial to remove carbon dioxide from industrial emissions. Published results Cell Reports PhysicsIt’s important because advanced carbon capture techniques are key to solving climate change, said Kyriakos Stilianou of OSU, who led the study. Carbon dioxide, a greenhouse gas, is produced by the burning of fossil fuels and is one of the main causes of global warming.

Plants that filter carbon from the air are starting to pop up all over the world – the world’s largest opened in Iceland in 2021 – but they are not ready to make a big impact on the world’s emissions problem, Stilianu says. The factory in Iceland can produce carbon dioxide in a year equivalent to the annual emissions of around 800 cars.

However, technologies for reducing carbon dioxide emissions at points of entry to the atmosphere, such as a factory, are relatively well developed. One of these technologies involves nanomaterials known as metal organic frameworks, or MOFs, that can trap carbon dioxide molecules through adsorption as flue gases pass through chimneys.

“Carbon capture is critical to achieving zero emissions targets,” said Stilianu, associate professor of chemistry. “MOFs have shown great promise for carbon capture due to their porosity and structural versatility, but their synthesis often means using reagents that are economically and environmentally expensive, such as heavy metal salts and toxic solvents.”

He also said that dealing with the water part of the flue gases makes it much more difficult to remove carbon dioxide. Many MOFs that exhibit carbon capture potential have lost their activity under humid conditions. Stilianu said the flue gases can be dried, but this adds significant costs.sufficient carbon dioxide removal process to render it unsuitable for industrial use.

“Therefore, we sought to develop MOFs to overcome several limitations of materials currently used for carbon capture: high cost, low selectivity for carbon dioxide, low stability in wet conditions, and low CO2 uptake,” he said.

MOFs are crystalline porous materials composed of positively charged metal ions surrounded by organic binding molecules known as ligands. The metal ions form knots that connect the arms of the binders and form a repeating lattice-like structure; The structure has nano-sized pores that adsorb gases like a sponge.

Stilianu said that MOFs can be designed with different components that determine the properties of the MOF, and there are millions of possible MOFs. About 100,000 have been synthesized by research chemists, and the properties of half a million more have been estimated.

“In this work, we present a MOF composed of aluminum and an easily available ligand, benzene-1,2,4,5-tetracarboxylic acid,” Stilianu said. Said. “The synthesis of MOF takes place in water and takes only a few hours. And the MOF has pores whose size is comparable to the size of CO molecules.₂So there’s limited space to capture carbon dioxide.”

The MOF works well in humid conditions and also prefers carbon dioxide over nitrogen, which is important because nitrogen oxides are a component of flue gases. Without such selectivity, the MOF would potentially bind to the wrong molecules.

“This MOF is an outstanding candidate for carbon capture after wet combustion,” Stilianu said. “It is cost-effective with outstanding separation efficiency and can be regenerated and reused at least three times with comparable absorption capacity.”