Robust MIL-96 tubular membranes for efficient separation of acetic acid/water mixtures by pervaporation

Abstract

Metal-organic framework (MOF) membranes hold great potential for acetic acid dehydration by pervaporation. However, it remains challenging to develop stable MOF membranes suitable for this application due to the corrosion of membranes by acetic acid. Herein, we report a robust aluminum (Al)-based MIL-96 membrane on porous ceramic tubes for acetic acid pervaporation dehydration. It is prepared by an induction strategy with Al-Sol@MIL-96-C layer, obtained by calcining an Al-based sol layer containing small MIL-96 seeds. The induced layer possesses a sponge-like structure and high reactivity, favoring the uniform growth of MIL-96 crystals and establishing a strong connection between the membrane layer and the support. The achieved MIL-96 membrane, with a thickness of ∼2 μm, exhibits excellent performance in separating 90 wt% acetic acid/water mixtures by pervaporation, showing a high separation factor of ∼3000 with a permeation flux of 1.54 kg/(m²·h). Notably, due to the connectivity of the Al-Sol@MIL-96-C layer, these membranes show long-term operational stability for over 200 h, as well as great tolerance to ultrasonic treatment, highlighting the enormous potential for applications. This work provides a feasible approach to fabricate robust MOF membranes for pervaporation separation of acetic acid/water mixtures.