Design and construction of homogeneous heterogeneity Co-Zn-ZIF-L membranes for efficient H2/CO2 separation

Abstract

Metal-organic framework (MOF) membranes have received widespread research attention as a novel membrane material for H2/CO2 separation. The preparation of MOF membranes can be extended by constructing MOF membranes with homogeneous heterogeneous structure and the MOF membranes with high permeance and high selectivity can be prepared. Here, we use the chelation-assisted interfacial growth process to construct a seeding layer, and then prepare Co-Zn-ZIF-L membranes with homogeneous heterogeneous structure by secondary growth for the efficient separation of H2/CO2. The resulting Co-Zn-ZIF-L membranes show an H2 permeances of 2156 GPU and the H2/CO2 selectivity of 31.6 at 298K and 1.0 bar, surpassing the Robeson upper bond (2008). Furthermore, the Co-Zn-ZIF-L membrane has a H2/CO2 separation stability of 65 h and can efficiently separate to obtain pure H2.