Pore-Nanospace Engineering of Mixed-Ligand Metal–Organic Frameworks for High Adsorption of Hydrofluorocarbons and Hydrochlorofluorocarbons

The
isostructural mixed-ligand metal–organic frameworks
(MOFs), LIFM-66, 66/67-mix, and 67, have been constructed via organic-linker
modification and variation to introduce different portions of functional
groups into the pore-nanospaces with tunable surface areas. Adsorption
measurements of hydrofluorocarbon (HFC) and hydrochlorofluorocarbon
(HCFC) with these MOFs reveal a record high uptake of R134a (1.09–1.14
g g–1) and an ultrahigh uptake of R22 (0.85–0.96
g g–1) under ordinary conditions of room temperature
and atmospheric pressure. Noteworthily, the adsorption performance
of greenhouse gases CO2, R134a, and R22 can be finely regulated
by introduced methyl groups, which has been elucidated by molecular
modeling and transient breakthrough simulations/experiments, demonstrating
an effective protocol of pore-nanospace engineering through rational
design of mixed-ligand MOFs for HFC and HCFC capture, sequestration,
and reclamation.