Efficient Separation of Acetylene-Containing Mixtures Using ZIF-8 Membranes

[Image: see text] Metal–organic framework (MOF) membranes show great potential in the separation of acetylene mixtures. In this work, we have prepared ZIF-8 membranes on polyamide (PA) substrates for the highly selective separation of acetylene/methane and acetylene/carbon dioxide mixtures. The C(2)H(2)/CH(4) and C(2)H(2)/CO(2) mixtures can be successfully separated using the ZIF-8 membranes, with separation factors of 12.1 and 1.8, respectively. Based on the results of the cross-permeation tests of C(2)H(2)/CH(4), CO(2)/CH(4), and C(2)H(2)/CO(2), the separation mechanism of C(2)H(2)/CH(4) in our ZIF-8 membrane can be attributed to a higher affinity for acetylene and molecular sieving effect, while C(2)H(2)/CO(2) separation is related to thermodynamic factors. It is worth noting that this is the first example of MOF membranes to successfully separate C(2)H(2) from CH(4) and CO(2).