Electrochemical synthesis of ZIF-8 membrane on commercial ceramic support for propylene/propane separation

The high-performance ZIF-8 membrane is the most promising candidate for propylene/propane separation. However, application-oriented ZIF-8 membranes should pay more attention to permeability and stability under high pressure. Herein, highly permeable and stable ZIF-8 membranes were developed on commercial ceramic support via an electrochemical synthesis strategy to efficiently separate propylene/propane. The effects of support surface roughness and synthesis parameters, including metal ion/ligand ratio and growth time on the microstructure of ZIF-8 membranes, were investigated, and the growth mechanism on the ceramic support surface was revealed by linear sweep voltammetry (LSV) and cyclic voltammetry (CV). Furthermore, the propylene permeance and separation factor of ultrathin ZIF-8 membranes (∼460 nm) reached 5.81 × 10⁻⁸ mol m⁻² s⁻¹ Pa⁻¹ and 86.3, respectively, showing excellent separation performance. It is worth noting that the ZIF-8 membrane exhibits reliable durability for laboratory pure and industrial raw gas at 6 bar, 55 °C conditions within 156 h. Thus, the reliable reproducibility, durability, and scalability of ZIF-8 membranes have significantly unlocked its commercialization potential.