Atmospheric water harvesting (AWH) is considered a promising strategy for sustainable freshwater production in landlocked and arid regions. Hygroscopic salt-based composite sorbents have attracted widespread attention for their water harvesting performance, but suffer from aggregation and leakage issues due to the salting-out effect. In this study, we synthesized a PML hydrogel composite by incorporating zwitterionic hydrogel (PDMAPS) and MIL-101(Cr) as a host for LiCl. The PML hydrogel was characterized using various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The swelling properties and water vapor adsorption-desorption properties of the PML hydrogel were also assessed. The results demonstrate that the MIL-101(Cr) was uniformly embedded into PDMAP hydrogel, and the PML hydrogel exhibits a swelling ratio of 2.29 due to the salting-in behavior. The PML hydrogel exhibited exceptional water vapor sorption capacity of 0.614 g/g at 298 K, RH = 40% and 1.827 g/g at 298 K, RH = 90%. It reached 80% of its saturated adsorption capacity within 117 and 149 min at 298 K, RH = 30% and 90%, respectively. Additionally, the PML hydrogel showed excellent reversibility in terms of water vapor adsorption after ten consecutive cycles of adsorption-desorption. The remarkable adsorption capacity, favorable adsorption-desorption rate, and regeneration stability make the PML hydrogel a potential candidate for AWH. This polymer-MOF synergistic strategy for immobilization of LiCl in this work offers new insights into designing advanced materials for AWH.

Separating light hydrocarbons (C₂H₆, C₃H₈, and C₄H₁₀) from CH₄ is challenging but important for natural gas upgrading. A microporous metal-organic framework, Zn(bdc)(ted)_0.5, based on terephthalic acid (bdc) and 1,4-diazabicyclo[2.2.2]octane (ted) ligands, is synthesized and characterized through various techniques, including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and porosity analysis. The adsorption isotherms of light hydrocarbons on the material are measured and the isosteric adsorption heats of CH₄, C₂H₆, C₃H₈, and C₄H₁₀ are calculated. The prediction of C2–4/C1 adsorption selectivities is accomplished using ideal adsorbed solution theory (IAST). The results indicate that the material exhibits exceptional characteristics, including a Brunauer-Emmett-Teller (BET) surface area of 1904 m²/g and a pore volume of 0.73 cm³/g. Notably, the material demonstrates remarkable C₂H₆ adsorption capacities (4.9 mmol/g), while CH₄ uptake remains minimal at 0.4 mmol/g at 298 K and 100 kPa. These findings surpass those of most reported MOFs, highlighting the material’s outstanding performance. The isosteric adsorption heats of C₂H₆, C₃H₈, and C₄H₁₀ on the Zn(bdc)(ted)_0.5 are higher than CH₄, suggesting a stronger interaction between C₂H₆, C₃H₈, and C₄H₁₀ molecules and Zn(bdc)(ted)_0.5. The molecular simulation reveals that Zn(bdc)(ted)_0.5 prefers to adsorb hydrocarbon molecules with richer C-H bonds and larger polarizability, which results in a stronger dispersion force generated by an adsorbent-adsorbate induced polarization effect. Therefore, the selectivity of C₄H₁₀/CH₄ is up to 180 at 100 kPa, C₃H₈/CH₄ selectivity is 67, and the selectivity of C₂H₆/CH₄ is 13, showing a great potential for separating C2–4 over methane.

Volatile organic compounds (VOCs) have been recognized as one of the major environmental hazards in the air. Metal organic frameworks (MOFs) and their associated materials have offered an excellent strategy for the adsorption removal of VOCs. In this work, we develop a facile and rapid synthesis method of HKUST-1, a typical and ideal Cu-based MOF, for VOC adsorption by using hydrotalcite as the intermediate for efficient crystallization at room temperature. The results show that HKUST-1 can be successfully synthesized within 10 s at room temperature. The as-synthesized HKUST-1 has a Brunauer-Emmett-Teller surface area of 2170.7 m² g⁻¹ and a total pore volume of 0.977 cm³ g⁻¹, which are among the highest reported values for such material. When tested for its benzene adsorption performance, the material can achieve a saturated adsorption capacity of 7.3 mmol g⁻¹ at 35 °C. Based on the temperature-programmed desorption result, it is shown that the activation energy for the benzene desorption is 68.23 kJ mol⁻¹. The material can demonstrate a relatively constant saturated adsorption capacity after several adsorption/desorption cycles, which indicates good regenerative performance.

The catalytic performances of alkylation can be maximized by optimizing the redox properties and pore architectures of zeolites.

Adsorption and separation of Xe/Kr are significant for making high-density nuclear energy environmentally friendly and for meeting the requirements of the gas industry. Enhancing the accuracy of the adsorbate model for describing the adsorption behaviors of Xe and Kr in MOFs and the efficiency of the model for predicting the separation potential (SP) value of Xe/Kr separation in MOFs helps in searching for promising MOFs for Xe/Kr adsorption and separation within a short time and at a low cost. In this work, polarizable and transferable models for mimic Xe and Kr adsorption behaviors in MOFs were constructed. Using these models, SP values of 38 MOFs at various temperatures and pressures were calculated. An optimal neural network model called BPNN-SP was designed to predict SP value based on physical parameters of metal center (electronegativity and radius) and organic linker (three-dimensional size and polarizability) combined with temperature and pressure. The regression coefficient value of the BPNN-SP model for each data set is higher than 0.995. MAE, MBE, and RMSE of BPNN-SP are only 0.331, −0.002, and 0.505 mmol/g, respectively. Finally, BPNN-SP was validated by experiment data from six MOFs. The transferable adsorbate model combined with the BPNN-SP model would highly improve the efficiency for designing MOFs with high performance for Xe/Kr adsorption and separation.