Synthesis of Fe–MOF/COF Hybrid Materials for Methane Adsorption Using Design of Experiments

This study focuses on the synthesis of Fe–MOF/COF (metal–organic framework/covalent organic framework) materials for methane adsorption. The synthesis process involves several steps, starting with the preparation of MIL-100(Fe) through the reaction of trimesic acid and iron(III) nitrate nonahydrate. MIL-100(Fe)_NH₂ is then synthesized by combining MIL-100(Fe) with ethylenediamine, followed by the synthesis of MIL-100(Fe)/COF through the addition of melamine, terephthalaldehyde, and dimethylsulfoxide. A definitive screening design and mixture method are employed to optimize the synthesis process by determining the influential factors and their respective ratios. The nitrogen content of samples is used as the response variable, and the optimized precursor molar ratio for MIL-100(Fe)/COF synthesis is estimated. From the main effect plots, TPA has the lowest effect on the response. The estimated actual precursor ratio for the optimized synthesis of MIL-100(Fe)/COF is MIL-100(Fe)_NH₂:TPA:MEL:DMSO:DIW = 1 mol:13 mol:10 mol:1884 mol:1648 mol. For the methane adsorption, the response optimizer indicated that MIL-100(Fe)/COF synthesized with a modified molar ratio of 0.1:0.4:0.5 (MEL:DMSO:DIW) was expected to exhibit the highest value.