Scientists at Chiba University in Japan have developed a new carbon material called viciazites that captures CO2 more efficiently and releases it at low temperatures. The material uses precisely arranged nitrogen groups to cut energy costs, potentially running on industrial waste heat. This breakthrough could make large-scale carbon capture more affordable.
A team led by Associate Professor Yasuhiro Yamada from the Graduate School of Engineering and Associate Professor Tomonori Ohba from the Graduate School of Science at Chiba University has created viciazites, carbon materials with controlled adjacent nitrogen functionalities. Published in the journal Carbon, the study details three versions: one with adjacent primary amine groups (-NH2) at 76% selectivity, another with adjacent pyrrolic nitrogen at 82%, and one with adjacent pyridinic nitrogen at 60% selectivity. These were produced by heating coronene, treating with bromine, and exposing to ammonia gas, among other methods, then applied to activated carbon fibers. Techniques like nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy confirmed the precise nitrogen placements. Tests showed that viciazites with adjacent -NH2 and pyrrolic nitrogen captured more CO2 than untreated fibers, while pyridinic versions performed similarly to standard materials. The standout feature is low-temperature desorption: materials with adjacent -NH2 groups release most captured CO2 below 60°C. 'Performance evaluation revealed that in carbon materials where NH2 groups are introduced adjacently, most of the adsorbed CO2 desorbs at temperatures below 60 °C. By combining this property with industrial waste heat, it may be possible to achieve efficient CO2 capture processes with substantially reduced operating costs,' Yamada said. Pyrrolic nitrogen versions need higher temperatures but offer greater stability. Yamada added, 'This work provides validated pathways to synthesize designer nitrogen-doped carbon materials, offering the molecular-level control essential for developing next-generation, cost-effective, and advanced CO2 capture technologies.' The materials could also remove metal ions or act as catalysts. The research received support from the Mukai Science and Technology Foundation, JSPS KAKENHI Grant JP24K01251, and MEXT's ARIM program.
