Development of Heterometallic Annular Tetranuclear Clusters in Metal-Organic Frameworks for Methane Purification and Storage.

ABSTRACT: Annular tetranuclear cluster based metal-organic frameworks (MOFs) have displayed unique advantages in gas adsorption and separation due to their highly connected robust architectures. Herein, two novel heterometallic tetranuclear motifs, [Y₂Cd₂(μ₃-O)₂(COO)₈(H₂O)₂] and [Y₂In₂(μ₃-O)₂(μ₂-O)₂(COO)₈(H₂O)₂], were successfully explored, which were further extended by 1,3,5-tris(4-carboxyphenyl)benzene (H₃BTB) tritopic linker to give isostructural MOFs (SNNU-326 and -327). SNNU-326 and -327 both exhibit the abilities to remove impurities (C₂-hydrocarbons and CO₂) in natural gas (NG) and excellent CH₄ storage capacities at high pressures. SNNU-326 shows better CH₄ purification and storage performance than SNNU-327 owing to different framework charges, in which only one counter ion is needed in SNNU-326 but two of them are necessary for SNNU-327, thus resulting in an obvious decrease of surface area. Dynamic breakthrough experiments demonstrate that SNNU-326 can effectively separate CH₄ from equimolar C₂H₂/CH₄, C₂H₄/CH₄, C₂H₆/CH₄, and CO₂/CH₄ mixtures with breakthrough interval times of about 40.6, 35.1, 54.2, and 10.2 min g^-1 (273 K, 1 bar, 2 mL min^-1), respectively. At the same time, SNNU-326 exhibits excellent CH₄ storage capability with total and working uptakes of 154.3 cm³ (STP) cm^-3 (80 bar) and 103.4 cm³ (STP) cm^-3 (5-65 bar) at 273 K on account of the collaborative impacts of adequate apertures, high surface areas, and multiple open metal sites.

SUBMITTER: Lei J 

PROVIDER: S-EPMC11792913 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature