The conversion of carbon dioxide (CO₂) into carbon monoxide (CO), an industrial feedstock, has attracted significant attention as a key step for producing synthetic fuels and chemical products. However, because CO₂ is a chemically stable molecule, the reaction typically requires high temperatures of 500–600 °C or higher, and catalyst performance often degrades during operation.
A research team led by Dr. Hyun-Tak Kim at the Korea Research Institute of Chemical Technology (KRICT), in collaboration with Prof. Young-Jin Kim of Kyungpook National University, Prof. Geunsik Lee of UNIST, and Prof. Sang-Joon Kim of Chungnam National University, has developed a dual-atom catalyst precisely engineered at the atomic level. The catalyst enables stable conversion of CO₂ to CO even under high-temperature thermochemical conditions.
Conventional CO₂ conversion catalysts typically use metal nanoparticles such as nickel (Ni), copper (Cu), or platinum (Pt). Increasing the metal content raises costs, and prolonged operation at high temperatures often leads to sintering—where metal particles agglomerate—reducing the number of active sites and degrading catalytic performance.
As an alternative approach, recent studies have explored single-atom catalysts (SACs), where isolated metal atoms are anchored onto carbon-based supports. While SACs maximize metal utilization, they still suffer from instability under thermal and structural stresses, as metal atoms can migrate and aggregate, eventually causing catalyst deactivation.
To overcome these limitations, the research team designed a catalyst in which copper and nickel are anchored as a dual-atom pair within a nitrogen-doped carbon framework, forming an N₂Cu–N₂–NiN₂ configuration. This atomically defined structure minimizes metal usage while maintaining high catalytic activity and stability.
The Cu-Ni dual-atom architecture promotes rapid CO₂ activation while enabling the product CO to desorb readily, thereby suppressing undesired methane (CH₄) formation. Because the metal atoms are strongly stabilized within the support, they remain atomically dispersed even under repeated high-temperature operation, avoiding the aggregation problems commonly observed in nanoparticle-based catalysts.
The synthesis route is also simpler and potentially more scalable than conventional methods that rely on specialized deposition techniques such as atomic layer deposition (ALD) or chemical vapor deposition (CVD). Instead, the catalyst can be prepared through a solution-based mixing, drying, and heat-treatment process. By increasing the precursor input under otherwise identical conditions, the researchers demonstrated reproducible synthesis of the Cu-Ni dual-atom catalyst (CuNi-DAC) at the 13-15 g scale, highlighting its promise for practical production.
In catalytic tests, the developed catalyst delivered CO₂ conversion approaching thermodynamic equilibrium with nearly 100% CO selectivity across the 300-600 °C range without detectable methane formation. Even under repeated temperature cycling, it maintained stable performance for more than 100 hours.
This achievement highlights the potential of the catalyst as a key material for the RWGS process. RWGS converts CO₂ into CO to produce syngas, which can subsequently be used to synthesize methanol, synthetic fuels, plastics, and various chemical products. Existing high-temperature RWGS catalysts can suffer from methane formation or structural degradation during long-term operation, whereas the newly developed catalyst offers a promising route to improved selectivity and durability.
Dr. Hyun-Tak Kim explained, “By precisely designing the Cu–Ni dual-atom structure, we demonstrated selective CO₂-to-CO conversion under high-temperature thermochemical conditions while preserving atomic dispersion even after repeated operation.” KRICT President Young-Guk Lee added, “This study demonstrates both the stability of atomically dispersed catalysts and the feasibility of scalable synthesis, which could contribute to strengthening Korea’s competitiveness in carbon-neutral technologies.”
The study was published in the November 2025 issue of the international journal Nature Communications (Impact Factor: 15.7) and was selected as an Editor’s Highlight. Kyung-Min Kim (KRICT) and Jinhong Mun (UNIST) served as co-first authors, and Dr. Hyun-Tak Kim (KRICT), Prof. Young-Jin Kim (Kyungpook National University), Prof. Geunsik Lee (UNIST), and Prof. Sang-Joon Kim (Chungnam National University) served as corresponding authors.
