超高比表面积碳基多孔吸附剂制备及其 Kr 气存储性能研究

The effective recovery and safe storage of Kr-85 can reduce the emission dose of radioactive gaseous effluents from nuclear facilities and reprocessing plants, which is of great significance to the safety of nuclear fuel cycle. Compared with the current stainless steel vessel storage technology, the solid porous adsorbent-based adsorption storage technology has the advantages of lower storage pressure and smaller storage volume. Developing large Kr gas adsorption capacity porous adsorbents is important for reducing Kr-85 pressure in storage vessels. Since high-energy electrons that released from Kr-85 can interact with metal elements, metal-organic framework adsorbents are not suitable for long-term Kr-85 storage. In this study, three carbon-based porous adsorbents (PAF-1, with a specific surface area of 5310 m²/g; HCP-2, with a specific surface area of 2887 m²/g; and XJTU-C, with a specific surface area of 2505 m²/g) were synthesized for Kr gas storage, and their Kr gas storage performance was studied in detail under different temperatures and pressures. The relationship between pore properties (such as specific surface area, pore size, and micropore proportion) and Kr gas storage capacity was analyzed using a high-pressure adsorption apparatus. PAF-1 with the highest specific surface area has a maximum absolute Kr adsorption capacity of 1270 mg/g at 2 MPa and 0℃. XJTU-C adsorbent has the highest Kr adsorption enthalpy and adsorption rate at 2 MPa and 0℃, with a Kr adsorption capacity of 1179 mg/g. HCP-2 has lower affinity for Kr molecules than XJTU-C, resulting in low high-pressure Kr adsorption capacity. This research analyzed the key factors affecting the storage performance of Kr gas and provided experimental support for the design of adsorbents with excellent Kr storage performance.