Synthesis and characterization of ZIF-69 membranes and separation for CO2/CO mixture

Abstract

Continuous and c-oriented ZIF-69 membranes were successfully synthesized on porous α-alumina substrates by an in situ solvothermal method. The membranes were characterized by XRD, SEM and single-gas permeation tests. The BET measurements on crystals taken from the same mother liquor that was used for membrane synthesis yield a Langmuir surface area of 1138m2/g. The stability of the membrane towards heat and different solvents were studied. Single-gas permeation experiments through ZIF-69 membranes were carried out by a vacuum method at room temperature using H2, CH4, CO, CO2 and SF6, respectively. The permeances were in the order of H2>CO2>CH4>CO>SF6. The separation of CO2/CO gas mixture was investigated by gas chromatograph (GC) and the permselectivity of CO2/CO was 3.5±0.1 with CO2 permeance of 3.6±0.3×10-8molm-2s-1Pa-1 at room temperature. © 2010 Elsevier B.V.