Nitrogen-rich three-dimensional porous crosslinked polymers for efficient capture of iodine vapor and methyl iodide...

Volatile radioiodine (I₂ and CH₃I) released during spent nuclear fuel reprocessing is difficult to efficiently capture under harsh conditions such as acidity, high humidity, and elevated temperature, thereby limiting the development of effective off-gas purification technologies. In this work, a combined theoretical-experimental strategy was employed to design a nitrogen-rich porous crosslinked polymer (Mel-POM) based on theoretical prediction. The as-prepared material features a three-dimensional interconnected pore structure and abundant nitrogen active sites, delivering high adsorption capacities of 4863.21 mg/g for I₂ and 907.76 mg/g for CH₃I. Mechanistic studies reveal that the adsorption is governed by the synergistic effect of pore filling and interactions between nitrogen sites and iodine species. Notably, the material maintains high uptake under harsh conditions (pH = 1 and 80% relative humidity), demonstrating excellent acid resistance and moisture tolerance. These results indicate that Mel-POM is a promising candidate for radioiodine abatement in complex off-gas environments and provides a viable strategy for the design of green and efficient adsorbents.