Room Temperature Synthesis Of MIL-100(Fe) And Its Adsorption Performances And Enhanced Water Stability Of TED@Cu-BTC

MOF material is a new type of adsorbent with excellent performance and has great potential in CO₂ capture and gas separation.However,most MOF materials are difficult to put into practical application due to the high cost and poor water vapor stability.In order to further reduce the cost and enhance the water vapor stability of MOFs,this paper explored a more energy-saving synthesis method of MIL-100?Fe?,and studied its adsorption and separation properties of CO₂and C1/C2/C3;TED@Cu-BTC material was synthesized using doping modification which effectively improved the water stability of Cu-BTC materials.This work has practical significance for further promoting the application of MOFs.?1?This paper developed a novel oxidizing radical-promoted method to prepare MIL-100?Fe?at room temperature without HF addition.The as-synthesized RT-MIL-100?Fe?showed a BET specific surface area of 2496.9 m²/g,and the adsorption capacity of CO₂ reached 3.57 mmol/g at 298K and 1 atm.Its IAST adsorption selectivity for CO₂/CH₄ was above 35.?2?The adsorption performance of RT-MIL-100?Fe?prepared at room temperature for C1/C2/C3 alkanes was investigated.The IAST-predicted adsorption selectivities of RT-MIL-100?Fe?reached 33.3 and 6.0 for C₃H₈/CH₄ and C₂H₆/CH₄ binary mixtures at 298K and 1 atm.Breakthrough experiments confirmed that C1/C2/C3 ternary gas mixtures can be well separated using the fixed bed of RT-MIL-100?Fe?at ambient condition.?3?TED@Cu-BTC material was prepared using ultra-fast room temperature synthesis method.TED@Cu-BTC material showed similar crystal characteristics to Cu-BTC and its BET surface area reached 1421 m²/g.The FTIR spectrum showed that TED is coordinated to the metal center through the Cu-N bond.In addition,TED@Cu-BTC material still maintained good CO₂adsorption performance,and the CO₂ adsorption capacity of TED_1/2@Cu-BTC reached 4.60mmol/g at 298K and 1 atm.?4?The water and water vapor stability of TED@Cu-BTC material is significantly enhanced.TED_1/2@Cu-BTC remained intact after 54 hours of water immersion and remained 94.6%of its CO₂ adsorption capacity.After exposure to humidity of 80%RH for 25 days,the TED@Cu-BTC material remained structurally intact,while the Cu-BTC material collapsed after 10 days of exposure.This is because TED was coordinated to the unsaturated metal sites and form a relatively strong Cu-N bond,which protected the Cu site from the attack of H₂O molecules and improved water stability of TED@Cu-BTC.