Facile Synthesis of Oriented Zr–MOF Membrane under Complete Room-Temperature Condition with Superb Selectivity for Carbon Capture

Owing to their tailorable structure deficiencies and intrinsic framework robustness, Zr–MOF membranes hold great promise in energy-efficient separation of diverse industrially important gas mixture, while their complete room-temperature (RT) production is extremely advantageous for large-scale application. Herein, we reported a facile complete RT protocol for preparing (111)-oriented UiO-66 membranes with CPO111/002 of 7.4 on ZrO2 buffer layer-modified porous α-Al2O3 substrate with a Zr(n-OPr)4 source. Experimental results indicated that carrying out the reaction at RT resulted in higher missing-linker numbers in the UiO-66 framework (1.5 per Zr6 formula unit) and therefore higher CO2/N2 adsorption selectivity, attributing to higher affinity interaction between CO2 and defective sites in Zr6-oxo cluster nodes. Benefiting from high linker deficiencies and low inter-crystalline defects, the ideal selectivity of CO2/N2 (36.5) on the prepared membrane was superior to the majority of polycrystalline MOF membranes measured under comparable conditions; moreover, unlike other hydrophilic membranes, our membrane manifested steady CO2/N2 separation performance under moisture conditions. The above reproducible protocol provides an appealing solution for alleviating residual concerns hindering the large-scale production of high-performance Zr–MOF membranes.