Enhanced one-step purification of C2H4 from C2H2/C2H4/C2H6 mixtures by fluorinated Zr-MOF

The extraction of C2H4 from C2H6/C2H4/C2H2 mixtures is of great significance in the chemical industry for C2H4 production but the process remains challenging due to the similarity of these C-2 hydrocarbon species in their molecular size and physical properties. Here, we report the fluorination of a stable Zr-MOF, UiO-66, to fine-tune the pore dimensions and pore functionality. In particular, UiO-66-CF3 shows notably preferential adsorption of C2H6 and C2H2 over C2H4, with C2H2/C2H4 and C2H6/C2H4 selectivities of 1.4 and 1.9, respectively. Theoretical calculations provide insight into the binding sites of UiO-66-CF3 for C-2 hydrocarbon adsorption. Breakthrough experiments further confirmed the capability of the material for purification of C2H4 from C2H2/C2H4/C2H6 ternary mixtures, evidenced by the high purity C2H4 (99.9%+) obtained directly from outlet gas.