Making clean fuel faster and cheaper with CO2

 Catalyst breakthrough converts CO2 into clean fuel faster and cheaper

A new copper-magnesium-iron catalyst transforms CO2 into CO at low temperatures with record-breaking efficiency and stability. The discovery paves the way for affordable, scalable production of carbon-neutral synthetic fuels. Researchers in Korea have created a low-temperature copper catalyst which converts CO2 into fuel components with record speed and efficiency. Research team has developed a catalyst which transforms carbon dioxide (CO2) into carbon monoxide (CO), a vital building block for sustainable synthetic fuels such as e-fuels and methanol. Team from the Korea Institute of Energy Research (KIER) has achieved a major technological breakthrough. This carbon monoxide is a vital building block for manufacturing synthetic fuels, such as e-fuels and methanol, marking a significant step toward carbon neutrality and the commercialisation of sustainable energy solutions.

Researchers in a team of scientists led by Dr. Kee Young Koo from the Hydrogen Research Department at the Korea Institute of Energy Research (President Yi Chang-Keun, hereafter referred to as KIER) has created a world-leading catalyst capable of transforming carbon dioxide, a major greenhouse gas, into an essential ingredient for producing eco-friendly fuels. The process, known as the reverse water-gas shift (RWGS) reaction, is a crucial technique for utilising captured CO2 as a feedstock. It reacts CO2 with hydrogen (H2) to produce CO and water (H2O). While the reaction typically requires high temperatures, above 800°C, to achieve high CO2 conversion, high heat often causes conventional nickel-based catalysts to degrade. At lower temperatures, common catalysts produce unwanted by-products like methane, reducing CO productivity.

The reverse water-gas shift (RWGS) reaction is a chemical process that converts carbon dioxide (CO2) into carbon monoxide (CO) and water (H2O) by reacting it with hydrogen (H2) in a reactor. The resulting carbon monoxide can then be combined with hydrogen to make syngas, a fundamental building block used to produce synthetic fuels. Because of its ability to recycle CO2 into usable fuel components, the RWGS reaction is seen as a promising pathway for advancing sustainable energy production. The KIER team, led by Dr. Kee Young Koo, successfully addressed these challenges by developing a cost-effective, abundant copper-based catalyst. The newly developed catalyst is a copper–magnesium–iron mixed oxide featuring a layered double hydroxide (LDH) structure. This innovative design incorporates iron and magnesium to fill the spaces between copper particles, effectively preventing particle agglomeration and significantly enhancing the catalyst’s thermal stability at lower operating temperatures. This structural stability is key, as copper-based catalysts can selectively produce only carbon monoxide at temperatures below 400 °C, avoiding methane formation.

Traditionally, the RWGS reaction operates best at temperatures above 800 °C. Nickel-based catalysts are often used because they can withstand such heat, but they lose performance over time as particles clump together, reducing surface area and efficiency. Operating at lower temperatures avoids this problem, but it also leads to the formation of unwanted by-products such as methane, lowering carbon monoxide output. To make the process more efficient and affordable, researchers have been searching for catalysts which remain highly active under low-temperature conditions. The KIER team succeeded by developing a new copper-based catalyst which delivers outstanding results at just 400 °C. Through real-time analysis, the researchers found that their catalyst bypasses the normal step of forming intermediate compounds. Instead, it directly converts CO2 into CO on the catalyst surface, which is why it maintains its high activity even at the relatively low temperature of 400 °C.

At 400 °C, the catalyst achieved a carbon monoxide yield of 33.4% and a formation rate of 223.7 micromoles per gram of catalyst per second (μmol·gcat⁻¹·s⁻¹), maintaining stability for over 100 continuous hours. These results represent a 1.7-fold higher formation rate and a 1.5-fold higher yield than standard copper catalysts. It is among the top-performing CO2 conversion catalysts in the world. The performance metrics of the new catalyst are ground breaking. Moreover, it outperformed noble metal catalysts like platinum by a factor of 2.2 in formation rate and 1.8 in yield, establishing it as one of the world’s best-performing catalysts for this reaction. The newly engineered copper-magnesium-iron mixed oxide catalyst outperformed commercial copper catalysts, producing carbon monoxide 1.7 times faster and with a 1.5 times higher yield at 400 °C. Copper catalysts have a key advantage over nickel: they can selectively produce only carbon monoxide at temperatures below 400 °C without forming methane. However, copper's thermal stability typically weakens near that temperature, leading to particle agglomeration and loss of activity.

To solve this challenge, Dr. Koo's team incorporated a layered double hydroxide (LDH) structure into their design. This layered structure contains thin metal sheets with water molecules and anions between them. By adjusting the ratio and type of metal ions, the researchers fine-tuned the catalyst's physical and chemical characteristics. Adding iron and magnesium helped fill the gaps between copper particles, effectively preventing clumping and improving heat resistance. Real-time infrared analysis and reaction testing revealed why the new catalyst performs so well. Conventional copper catalysts convert CO2 into carbon monoxide through intermediate compounds called formates. The new material, however, bypasses these intermediates entirely, converting CO2 directly into CO on its surface. Because it avoids side reactions which produces methane or other by-products, the catalyst maintains high activity even at a relatively low temperature of 400 °C. Dr. Koo hailed the low-temperature CO2 hydrogenation catalyst technology as a “breakthrough achievement” which enables efficient CO production using inexpensive, abundant materials. As CO is an essential precursor for syngas, which in turn is the building block for synthetic fuels like e-fuels for aviation and shipping, this discovery has immense potential for hard-to-decarbonise sectors.

"The low-temperature CO2 hydrogenation catalyst technology is a breakthrough achievement that enables the efficient production of carbon monoxide using inexpensive and abundant metals," said Dr. Kee Young Koo, the project's lead researcher. "It can be directly applied to the production of key feedstocks for sustainable synthetic fuels. Moving forward, we will continue our research to expand its application to real industrial settings, thereby contributing to the realization of carbon neutrality and the commercialization of sustainable synthetic fuel production technologies." The study was supported by the KIER's R&D project, 'Development of e-SAF (sustainable aviation fuel) production technology from carbon dioxide and hydrogen. E-Fuels are synthetic fuels produced by combining green hydrogen, generated with renewable electricity, and captured CO2 from the atmosphere or sustainable biomass. They are emerging as a promising alternative to conventional fossil fuels, especially for hard-to-decarbonize sectors such as aviation and shipping. The research findings were published in the high-impact journal Applied Catalysis B: Environmental and Energy, signalling a major advance in the global effort to recycle CO2 and accelerate the transition to sustainable energy.