Fabrication of tubular ZIF-67 membranes via a highly active seeding-induction strategy for enhanced propylene /propane separation

Despite showing great potential in C 3 H 6 refinement, controllable synthesis of pressure-resistant ZIF-67 membranes with high propylene/propane (C 3 H 6 /C 3 H 8 ) separation performance remains very challenging. In this work, we prepared robust tubular ZIF-67 membrane for efficient C 3 H 6 /C 3 H 8 separation via a highly active seeding-induction strategy. Combination of Ag complex-loaded ZIF-8 nanoparticle seed layer and the ZnO nanocrystal layer enabled abundant heterogeneous nucleation and high-affinity π-complexation interaction with C 3 H 6 , the Ag(I)-incorporated ZIF-67 membrane exhibited enhanced C 3 H 6 permeance of 1.1 × 10 −9  mol·m −2 ·s −1 ·Pa −1 and C 3 H 6 /C 3 H 8 separation factor of 50, which were 45 and 1.3 times higher than that of parent ZnO induced ZIF-67 membrane. The obtained tubular Ag(I)-incorporated ZIF-67 membranes demonstrated a steady C 3 H 6 /C 3 H 8 separation factor under elevated feed pressure (1–7 bar) owing to the robust microstructure. Furthermore, the present ZIF-67 membrane exhibited outstanding long-term durability over 80 days. Thus, this work provides a great potential of the robust ZIF-67 membrane toward reliable separation of C 3 H 6 /C 3 H 8 mixture.