Oregon State unveils titanium molecule for safer, cheaper, and more efficient CO2 capture.

In a breakthrough that could revolutionize efforts to combat climate change, researchers at Oregon State University have unveiled a titanium-based molecule capable of capturing carbon dioxide directly from the air, offering a cheaper, safer, and more efficient alternative to existing carbon capture methods, and paving the way for large-scale implementation in the global push for a cleaner future.

Emerging as a leader in the field of carbon capture in recent years, OSU has explored innovative materials like aluminum-based frameworks and vanadium peroxides to trap and store atmospheric CO2.

Through vanadium, the researchers aimed to create a high-capacity material capable of efficiently converting CO2 into stable forms, offering insights into the role of transition metals in carbon capture.

These findings likely informed subsequent exploration into aluminum-based frameworks, where the focus shifted to overcoming challenges related to cost, scalability, and performance in variable conditions.

However, this pursuit for more practical and scalable solutions led the team to explore a different material, one found in nearly everything.

Wikimedia Commons; Chemical Elements Virtual Museum

Known as the ninth most abundant material on Earth, ironically, titanium "sponge" is the name of its precursor form before being made into a metal, a quality apparently shared in an effective carbon capture material.

"We opted to look into titanium as it's 100 times cheaper than vanadium, more abundant, more environmentally friendly and already well established in industrial uses," said Karlie Bach, a graduate student who worked on the study.

Part of a larger, federally funded initiative to advance direct air capture (DAC) technologies, this titanium-based research was supported by a $24 million investment from the U.S. Department of Energy in 2021.

Currently, DAC still faces many significant obstacles, including the low concentration of CO2 in the atmosphere – around 0.04% – which makes the process inherently more difficult and energy-intensive than capturing emissions at industrial sources.

Driven by the potential for a cost-effective and widely applicable approach, the research team synthesized a titanium-based molecule with a unique structure, making it particularly effective at capturing CO2 directly from the air.

Among their discoveries, one material, potassium tetraperoxo titanate (a potassium titanium oxide), stood out for its ability to not only capture more carbon dioxide than previous materials but also release oxygen gas during the process, making it more efficient and effective.

"One of the standout discoveries is potassium tetraperoxo titanate," said Bach. "Not only does it capture carbon dioxide with impressive efficiency, but it also releases oxygen gas during the process. This reaction creates a spongelike structure, allowing reactivity to occur throughout the crystals, not just on the surface."

The breakthrough was made possible by creating titanium molecules with a tetraperoxo structure – a configuration that allows the titanium atom to coordinate with four peroxide groups – a unique arrangement that enhances reactivity, enabling the molecules to efficiently scrub CO2 from the air.

"Our favorite carbon capture structure we discovered is potassium tetraperoxo titanate, which is extra unique because it turns out it is also a peroxosolvate," added Bach. "That means that in addition to having the peroxide bonds to titanium, it also has hydrogen peroxide in the structure, which is what we believe makes it so reactive."

The significance of OSU's titanium-based discovery becomes clear when compared to current DAC technologies. Facilities like Climeworks' Orca plant in Iceland, the largest operational DAC facility in the world, captures around 4,000 tons of CP2 annually.

This equates to roughly 1.1 millimoles of CO2 captured per gram of material per hour – a measure far outperformed by the research team's new material, which demonstrated a capture capacity of 8.5 millimoles per gram.

This nearly eightfold molecular efficiency highlights the transformative potential of OSU's material when scaled for broader applications.

While DAC technologies hold promise, they remain in their infancy, with only 18 operational facilities worldwide collectively capturing less than 0.01 million tons of carbon dioxide annually.

OSU's titanium-based molecule directly addresses many of the present obstacles that DAC faces with its high capture capacity and cost-effectiveness. As the International Energy Agency predicts over 130 new DAC plants in development globally, advancements like OSU's discovery could provide the efficiency and scalability required to meet international climate goals.