Two new metal-organic frameworks: Synthesis, characterization, gas adsorption and simulation

A microporous Ce-based MOF with the octahedron cage for highly selective adsorption towards xenon over krypton

The collection of high-purity noble gases with recyclable nuclides provides substantial economic benefits and minimizes the risk of environmental pollution, which is a future development tendency for nuclear industries. Here, Ce-SINAP-1, with its radiation-resistance (up to 20 kGy of γ-ray irradiation) and suitable pore channels for the separation of noble gases (Ar, Kr and Xe), was synthesized. Ce-SINAP-1 exhibited the selective adsorption of Xe (2.02 mmol g⁻¹) over Kr (0.67 mmol g⁻¹) and Ar (0.27 mmol g⁻¹) at 293 K (1 bar) with a Henry's selectivity of 8.24 (Xe/Kr), and an ideal adsorbed solution theory selectivity of 14.9 (Xe : Kr 20 : 80). The result of the dynamic breakthrough experiment also indicates a good separation for Xe/Kr with Ar.

A high selectivity of Xe over Kr at 293 K was achieved by a 3D Ce-based organic framework due to the geometric features. Favorable thermal stability and ionizing radio-resistance render it a promising candidate for radioactive inert gases treatment.