Year: 2025
Type: article
Abstract: Metal-organic frameworks (MOFs) with high-density uncoordinated open metal sites have been intensively investigated in Xe/Kr separation because of their strong and selective interaction with Xe. However, the dynamic Xe/Kr separation behavior of these MOFs is often unsatisfactory in practical applications due to slow diffusion kinetics. This work presents a facile two-step method to synthesize hollow Ni-MOF-74 particles with short diffusion lengths to enhance dynamic Xe/Kr separation. Unlike conventional sacrificial template approaches, where a crystalline MOF layer is directly grown on to the template surface, this method first rapidly deposits a metal-ligand complex layer under mild reaction conditions while the template undergoes simultaneous degradation. These poorly crystalline yet well-faceted hollow capsules are then reconstructed into crystalline hollow Ni-MOF-74 particles of the same morphology. Xe adsorption kinetics analyses show that the Xe diffusion rate of hollow Ni-MOF-74 was 1.5 times faster than that of solid Ni-MOF-74 despite their identical Xe and Kr adsorption capacity and selectivity. As a result, the enhanced diffusion kinetics of the hollow structure resulted in a steeper breakthrough curve and a 17% increase in breakthrough time than its solid counterpart during column separation of a Xe/Kr mixture.
Source: Nanoscale Advances
DOI: 10.1039/d5na00064e
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,962
Funders: National Natural Science Foundation of China, Chinese Academy of Sciences, Youth Innovation Promotion Association of the Chinese Academy of Sciences, Natural Science Foundation of Gansu Province, Natural Science Foundation for Young Scientists of Shanxi Province, Young Scientists Fund, Youth Innovation Promotion Association
OpenAlex ID: W4409420830