Zr6-Cluster-Embedded ZIF-8 Membranes Fabricated by Electrochemical Deposition for CO2/N2 and CO2/CH4 Separation.

Abstract

Membrane-based separation technology holds great promise for CO2 capture, yet conventional membranes are often constrained by the permeability-selectivity trade-off. In this study, we developed a zirconium-cluster (Zr6)-incorporated ZIF-8 membrane via an electrochemical synthesis strategy to address this limitation. The resulting Zr6@ZIF-8 composite membrane exhibits high crystallinity, a dense microstructure, and homogeneous dispersion of Zr6 clusters within the ZIF-8 framework. The optimized Zr6@ZIF-8-2 membrane demonstrates outstanding CO2 separation performance with a CO2 permeance of up to 300.0 gas permeation unit and CO2/N2 and CO2/CH4 selectivities of 27.0 and 14.8, respectively. The Zr6 clusters enable effective structural regulation of ZIF-8 membranes, resulting in enhanced CO2 separation performance and leading to improved diffusion selectivity. Furthermore, the membrane shows a stable separation performance under varying feed pressures and temperatures, along with excellent long-term operational stability. This work provides an effective electrochemical approach for fabricating high-performance MOF-based membranes, offering a promising candidate for industrial CO2 capture and natural-gas purification.