Scientists have developed a fast and energy efficient way to produce advanced carbon materials capable of capturing carbon dioxide, a major greenhouse gas driving climate change. The new method dramatically reduces production time while improving adsorption performance, offering a promising pathway toward low cost carbon capture technologies.
In a recent study, researchers designed a novel strategy that combines pre oxidation treatment with microwave activation to create nitrogen doped ultramicroporous carbon derived from coal. The material demonstrates exceptional ability to capture and selectively separate carbon dioxide from gas mixtures.
"Carbon capture technologies must become faster, more efficient, and scalable if we hope to meet global climate targets," said the study's corresponding author. "Our work shows that microwave assisted synthesis can simultaneously improve material performance while dramatically reducing energy consumption."
Carbon based adsorbents are widely studied for carbon dioxide capture because of their high stability and tunable pore structures. However, traditional preparation methods rely on long periods of high temperature heating, often lasting more than an hour, which consumes large amounts of energy and limits the retention of key functional elements that enhance adsorption performance. The new microwave based approach addresses these challenges by using volumetric heating to rapidly activate carbon precursors and preserve nitrogen and oxygen functional groups that strongly attract carbon dioxide molecules.
The research team used Ningdong coal as a raw material and introduced an innovative pre oxidation step before microwave processing. This pretreatment creates oxygen containing active sites that enable efficient incorporation of nitrogen atoms during microwave activation. The resulting carbon material contains a high concentration of adsorption active sites and a large number of ultramicropores with widths between 0.6 and 0.7 nanometers, which closely match the size of carbon dioxide molecules.
Experimental results show that the optimized carbon sample achieved a carbon dioxide uptake capacity of 4.72 millimoles per gram at zero degrees Celsius and 3.33 millimoles per gram at room temperature. The material also demonstrated strong selectivity for carbon dioxide over nitrogen, which is essential for practical gas separation applications.
Beyond performance improvements, the new method offers significant energy savings. Conventional activation processes typically require high power furnace heating for extended periods, consuming large amounts of electricity. In contrast, the microwave synthesis approach can produce high quality activated carbon within approximately ten minutes while maintaining high microwave absorption efficiency. This rapid processing reduces overall energy consumption by nearly two orders of magnitude.
The study also revealed important insights into how pore structure and surface chemistry work together to enhance carbon capture performance. Increasing nitrogen doping improved the chemical affinity of the carbon surface toward carbon dioxide molecules, while ultramicroporous structures strengthened physical adsorption through strong molecular confinement effects.
"The synergy between surface functional groups and precisely controlled pore structures is the key to achieving high adsorption efficiency," the researchers explained. "Our findings provide new guidance for designing next generation porous carbon materials for carbon capture and gas separation."
The researchers believe that their scalable synthesis strategy could accelerate the development of industrial carbon capture technologies. Because the process uses inexpensive coal resources and rapid microwave heating, it offers strong potential for large scale manufacturing of advanced adsorbents.
As global demand for carbon capture solutions continues to grow, innovations such as this microwave assisted synthesis approach may play a crucial role in reducing greenhouse gas emissions and supporting the transition toward carbon neutrality.
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Journal reference: Feng Y, Meng X, Li J, Xue N, Li W, et al. 2026. Rapid microwave synthesis of nitrogen-doped ultramicroporous coal-based carbon with enhanced CO2 adsorption performance. Sustainable Carbon Materials 2: e006 doi: 10.48130/scm-0026-0001
https://www.maxapress.com/article/doi/10.48130/scm-0026-0001
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About Sustainable Carbon Materials :
Sustainable Carbon Materials (e-ISSN 3070-3557) is a multidisciplinary platform for communicating advances in fundamental and applied research on carbon-based materials. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon materials around the world to deliver findings from this rapidly expanding field of science. It is a peer-reviewed, open-access journal that publishes review, original research, invited review, rapid report, perspective, commentary and correspondence papers.
