Purification of C 2 H 4 from a ternary C 2 H 2 /C 2 H 6 /C 2 H 4 mixture by one-step adsorption separation is of prime importance but challenging in the petrochemical industry; however, effective strategies to design high-performance adsorbents are lacking. We herein report for the first time the incorporation of Lewis basic sites into a C 2 H 6 -selective MOF, enabling efficient one-step production of polymer-grade C 2 H 4 from ternary mixtures. Introduction of amino groups into highly stable C 2 H 6 -selective UiO-67 can not only partition large pores into smaller cagelike pockets to provide suitable pore confinement but also offer additional binding sites to simultaneously enhance C 2 H 2 and C 2 H 6 adsorption capacities over C 2 H 4 . The amino-functionalized UiO-67-(NH 2 ) 2 thus exhibits exceptionally high C 2 H 2 and C 2 H 6 uptakes as well as benchmark C 2 H 2 /C 2 H 4 and C 2 H 6 /C 2 H 4 selectivities, surpassing all of the C 2 H 2 /C 2 H 6 -selective materials reported so far. Theoretical calculations combined with in situ infrared spectroscopy indicate that the synergetic effect of suitable pore confinement and functional surfaces decorated with amino groups provides overall stronger multipoint van der Waals interactions with C 2 H 2 and C 2 H 6 over C 2 H 4 . The exceptional performance of UiO-67-(NH 2 ) 2 was evidenced by breakthrough experiments for C 2 H 2 /C 2 H 6 /C 2 H 4 mixtures under dry and wet conditions, providing a remarkable C 2 H 4 productivity of 0.55 mmol g −1 at ambient conditions.

Water adsorption in porous materials is important for many applications including heat allocation, dehumidification, thermal batteries, and water harvesting from air. While porous MOFs have been demonstrated as promising adsorbents...

Porous physisorbents are attractive candidates for selective capture of trace gas or volatile compounds due to their low energy footprints. However, many physisorbents suffer from insufficient sorbate-sorbent interactions, resulting in low uptake or inadequate selectivity when gases are present at trace levels. Here, we report a strategy of programmed fluorine binding engineering in anion-pillared metal-organic frameworks to maximize C 2 H 2 binding affinity for benchmark trace C 2 H 2 capture from C 2 H 4 . A robust material (ZJU-300a) was elaborately designed to provide multiple-site fluorine binding model, resulting in an ultrastrong C 2 H 2 binding affinity. ZJU-300a exhibits a record-high C 2 H 2 uptake of 3.23 millimoles per gram (at 0.01 bar and 296 kelvin) and one of the highest C 2 H 2 /C 2 H 4 selectivity (1672). The adsorption binding of C 2 H 2 and C 2 H 4 was visualized by gas-loaded ZJU-300a structures. The separation capacity was confirmed by breakthrough experiments for 1/99 C 2 H 2 /C 2 H 4 mixtures, affording the maximal dynamic selectivity (264) and C 2 H 4 productivity of 436.7 millimoles per gram.

Developing efficient and stable water adsorbents for adsorption-driven heat transfer technology still remains a challenge due to the lack of efficient strategies to enhance low-pressure water uptakes. The authors herein demonstrate that the immobilization of Lewis basic nitrogen sites into metal-organic frameworks (MOFs) can improve water uptake and target benchmark coefficient of performances (COPs) for cooling and heating. They present the water sorption properties of a chemically stable MOF (termed as Zr-adip), designed by incorporating hydrophilic nitrogen sites into the adsorbent MIP-200. Zr-adip exhibits S-shaped sorption isotherms with an extremely high water uptake of 0.43 g g −1 at 303 K and P/P 0 = 0.25, higher than MIP-200 (0.39 g g −1 ), KMF-1 (0.39 g g −1 ) and MOF-303 (0.38 g g −1 ). Theoretical calculations reveal that the incorporated N sites can serve as secondary adsorption sites to moderately interact with water, providing more binding sites to strengthen the water binding affinity. Zr-adip achieves exceptionally high COPs of 0.79 (cooling) and 1.75 (heating) with a low driving temperature of 70 °C, outperforming MIP-200 (0.78 and 1.53) and KMF-1 (0.75 and 1.74). Combined with its ultrahigh stability, excellent cycling performance, and easy regeneration, Zr-adip represents one of the best water adsorbents for adsorption-driven cooling and heating.

Utilization of rigid, highly connected organic linkers is critical for the reticular synthesis of functional metal–organic frameworks (MOFs). However, highly‐stable MOFs (e.g. Al/Cr/Zr‐based MOFs) based on rigid ligands with more than 6 coordinating functions have been rarely achieved thus far. Herein, we describe the construction of two bcu Zr‐based MOFs (named ZrMOF‐1 and ZrMOF‐2) from peripherally extended pentiptycene ligands (H8PEP‐1 and H8PEP‐2) with rigid quadrangular prism shape possessing 8 carboxylic groups at the prism vertices. Particularly, ZrMOF‐1 exhibits microporous structure with large Bruno‐Emmett‐Teller surface area and high water stability, endowing it a promising water harvesting material with a high water uptake capacity of 0.83 gH2O gMOF−1 at P/P0=0.90 and 25 °C, a steep uptake at a low P/P0 of 0.30, and excellent durability over 500 water adsorption‐desorption cycles. Moreover, self‐consistent charge density functional tight‐binding calculations were carried out, rationalizing the water adsorbing process and amount in ZrMOF‐1.