A LDH Template Triggers the Formation of a Highly Compact MIL-53 Metal-Organic Framework Membrane for Acid Upgrading

Highly compact metal-organic framework (MOF) membranes offer hope for the ambition to cope with challenging separation scenarios with industrial implications. A continuous layer of layered double hydroxide (LDH) nanoflakes on an alumina support as a template triggered a chemical self-conversion to a MIL-53 membrane, with approximately 8 hexagonal lattices (LDH) traded for 1 orthorhombic lattice (MIL-53). With the sacrifice of the template, the availability of Al nutrients from the alumina support was dynamically regulated, which resulted in synergy for producing membranes with highly compact architecture. The membrane can realize nearly complete dewatering from formic acid and acetic acid solutions, respectively, and maintain stability in a continuous pervaporation over 200 h. This is the first success in directly applying a pure MOF membrane to such a corrosive chemical environment (lowest pH value of 0.81). The energy consumption is saved by up to 77 % when compared with the traditional distillation.

Automated summary

Highly compact metal-organic framework (MOF) membranes show promise in tackling challenging separation scenarios with industrial implications. Through a chemical self-conversion process, a continuous layer of layered double hydroxide (LDH) nanoflakes on an alumina support can transform into a MIL-53 membrane, resulting in highly compact architecture. This membrane can effectively dehydrate formic acid and acetic acid solutions and maintain stability in a corrosive chemical environment with a pH as low as 0.81. The energy consumption is significantly reduced compared to traditional distillation, saving up to 77%.