Engineering pore nanospaces by introducing aromatic effects in UiO-66 for efficient separation of light hydrocarbons

Abstract

Natural gas, as one of the most widely used clean energies, has attracted significant attention due to its abundance, safe nature, and low cost but requires further separation and purification to produce downstream commodities more efficiently. In this case, the simultaneous removal of ethane and propane from natural gas is very important but challenging due to their similar physical and chemical properties. Herein, a pore-nanospace-engineering strategy was developed to construct a series of UiO-66-type zirconium MOFs by introducing different aromatic linkers, i.e., UiO-66, UiO-66-Naph, DUT-52 and UiO-66-Anth, for natural gas separation and purification, revealing that the appropriate aromatic effect plays a vital role in the separation of the ternary C₃H₈/C₂H₆/CH₄ gas mixture. Specifically, UiO-66-Naph exhibited the best C₂/C₃ (C₂H₆ and C₃H₈) light hydrocarbon separation potential from CH₄, indicating that the introduction of naphthalene moieties not only effectively reduced the pore size but also provided a suitable aromatic pore-environment for C₂H₆/C₃H₈-framework interactions through dispersion and induction forces, which was corroborated by theoretical calculations and transient breakthrough experiments.