Self-Adjusting Metal-Organic Framework for Efficient Capture of Trace Xenon and Krypton

The capture of the xenon and krypton from nuclear reprocessing off-gas is essential to the treatment of radioactive waste. Although various porous materials have been employed to capture Xe and Kr, the development of high-performance adsorbents capable of trapping Xe/Kr at very low partial pressure as in the nuclear reprocessing off-gas conditions remains challenging. Herein, we report a self-adjusting metal-organic framework based on multiple weak binding interactions to capture trace Xe and Kr from the nuclear reprocessing off-gas. The self-adjusting behavior of ATC-Cu and its mechanism have been visualized by the in-situ single-crystal X-ray diffraction studies and theoretical calculations. The self-adjusting behavior endows ATC-Cu unprecedented uptake capacities of 2.65 and 0.52 mmol g(-1) for Xe and Kr respectively at 0.1 bar and 298 K, as well as the record Xe capture capability from the nuclear reprocessing off-gas. Our work not only provides a benchmark Xe adsorbent but proposes a new route to construct smart materials for efficient separations.

Automated summary

This study reports a self-adjusting metal-organic framework based on multiple weak binding interactions for capturing trace amounts of xenon and krypton from nuclear reprocessing off-gas. The self-adjusting behavior of ATC-Cu and its mechanism have been visualized and studied. The results show that ATC-Cu exhibits unprecedented high uptake capacities and record xenon capture capability from the nuclear reprocessing off-gas. This work not only provides a benchmark xenon adsorbent, but also proposes a new route for constructing smart materials for efficient separations.