A robust ethane-trapping metal-organic framework for efficient purification of ethylene

Machine Learning-Assisted Discovery of Propane-Selective Metal-Organic Frameworks

Machine learning is gaining momentum in the prediction and discovery of materials for specific applications. Given the abundance of metal-organic frameworks (MOFs), computational screening of the existing MOFs for propane/propylene (C3H8/C3H6) separation could be equally important for developing new MOFs. Herein, we report a machine learning-assisted strategy for screening C3H8-selective MOFs from the CoRE MOF database. Among the four algorithms applied in machine learning, the random forest (RF) algorithm displays the highest degree of accuracy. We experimentally verified the identified top-performing MOF (JNU-90) with its benchmark selectivity and separation performance of directly producing C3H6. Considering its excellent hydrolytic stability, JNU-90 shows great promise in the energy-efficient separation of C3H8/C3H6. This work may accelerate the development of MOFs for challenging separations.

Redox induced controlling microporosity of zeolitic transition metal oxides based on ε‑Keggin ironmolybdate in an ultra-fine level

Tuning microporosity of crystalline microporous materials is critical for achieving good application performance. Zeolitic ironmolybdate shows both redox property and microporosity, and a redox-triggered microporosity change is investigated. The micropore...

Improving Ethane/Ethylene Separation Performance of Isoreticular Metal-Organic Frameworks via Substituent Engineering

The preferential capture of ethane (C₂H₆) over ethylene (C₂H₄) presents a very cost-effective and energy-saving means applied to adsorptive separation and purification of C₂H₄ with a high product purity, which is however challenged by low selectivity originating from their similar molecular sizes and physical properties. Substituent engineering has been widely employed for selectivity regulation and improvement, but its effect on C₂H₆/C₂H₄ separation has been rarely explored to date. In this work, four isoreticular coordination framework compounds based on 5-(pyridin-3-yl)isophthalate ligands bearing different substituents were rationally constructed. As revealed by isotherm measurements, thermodynamic studies, and IAST computations, they exhibited promising utility for C₂H₆/C₂H₄ separation with moderate adsorption heat and a high uptake amount at a relatively low-pressure domain. Furthermore, the C₂H₆/C₂H₄ separation potential can be finely tuned and optimized via purposeful substituent alteration. Most remarkably, functionalization with a nonpolar methyl group yielded an improved separation efficiency compared to its parent compound. This work offers a good reference value for enhancing the C₂H₆/C₂H₄ separation efficiency of MOFs by engineering the pore microenvironment and dimensions via substituent manipulation.