Aluminum-based MOF for efficient iodine and methyl iodide capture from NO2-containing gas streams

The capture of radioactive gaseous iodine is essential for the sustainable development of nuclear energy and the long-term safe supply of nuclear fuel. However, the presence of nitrogen oxides in the exhaust gas generated during spent fuel reprocessing poses significant challenges to the stability of iodine adsorbents. It is crucial to consider the impact of NOx on the structure and adsorption performance of the materials. We report here the development of an aluminum-based metal–organic framework (MOF), CAU-1, engineered for efficient iodine capture. Synthesized through a cost-effective and straightforward method, CAU-1 exhibits excellent structural stability and robust adsorption performance, with a maximum iodine vapor adsorption capacity of 1277.18 mg/g at 130 °C and methyl iodide adsorption capacity of 533.10 mg/g, highlighting its potential for efficient iodine vapor removal. Notably, CAU-1 retains its structural integrity and iodine adsorption performance even in the presence of 5 % NO 2 , maintaining high adsorption capacities for I 2 (1129.41 mg/g) and CH 3 I (436.79 mg/g). Mechanistic analysis revealed the key role of the –NH 2 group in the iodine adsorption process. Additionally, co-adsorption studies with I 2 and NO 2 showed that CAU-1 can still capture iodine in the form of both I 2 and I 3 - in the presence of NO 2 . This study illustrates the potential of CAU-1 as an effective industrial adsorbent for removing iodine from NO 2 -containing gas streams.