Efficient propyne/propadiene separation by microporous crystalline physiadsorbents

Abstract

Selective separation of propyne/propadiene mixture to obtain pure propadiene (allene), an essential feedstock for organic synthesis, remains an unsolved challenge in the petrochemical industry, thanks mainly to their similar physicochemical properties. We herein introduce a convenient and energy-efficient physisorptive approach to achieve propyne/propadiene separation using microporous metal-organic frameworks (MOFs). Specifically, HKUST-1, one of the most widely studied high surface area MOFs that is available commercially, is found to exhibit benchmark performance (propadiene production up to 69.6 cm3/g, purity > 99.5%) as verified by dynamic breakthrough experiments. Experimental and modeling studies provide insight into the performance of HKUST-1 and indicate that it can be attributed to a synergy between thermodynamics and kinetics that arises from abundant open metal sites and cage-based molecular traps in HKUST-1.

Robust and Radiation-Resistant Hofmann-Type Metal–Organic Frameworks for Record Xenon/Krypton Separation

“…Physisorption separation based on porous materials has attracted extensive interest from both academic and industrial communities because of their great potential to mitigate the high energy consumption associated with chemical separations. − Many porous materials, such as metal–organic frameworks (MOFs), organic cages, and zeolites, have been widely exploited for Xe/Kr separation. − Among them, microporous MOFs have demonstrated superior advantages over other porous materials for various gas separations because of their powerful designability and tunability over pore size/shape and pore chemistry. − While a number of MOF materials have been realized for xenon/krypton separation, it still remains a daunting challenge to achieve ultrahigh Xe/Kr adsorption selectivity, since xenon and krypton are both inert atomic gases without dipole or quadrupole moments. − Pore tuning and pore functionalization are two powerful approaches to increase the Xe affinity and thus achieve high Xe/Kr separation performance. For example, extensive endeavors have been devoted to the incorporation of polar groups or open metal sites (OMSs) into porous MOFs to enforce the Xe adsorption affinity and enhance Xe/Kr selectivity. − The well-established materials are those with high density of OMSs, such as MOF-74 and UTSA-74.…”

Sub‐Nanoporous Engineered Fibrous Aerogel Molecular Sieves with Nanogating Channels for Reversible Molecular Separation

“…Of note, the size‐driving mode solely relies on the size difference between target molecules, which would be mitigated by the identical polarity. [ 16 ] Moreover, the huge difficulty has remained of thermodynamic mode for molecular mixtures with extremely small size (<1 nm), as the sub‐1 nm molecules could not be effectively trapped due to the lacking size‐induced overlapped adsorption potential. [ 17 ] Here, we tackle the challenge of specifically separating miscible molecular mixtures with sub‐1 nm size and different polarity and propose a size‐thermodynamic dual‐driving separation mode using reversible NAMSs with precise sub‐1 nm adsorption traps.…”

The unique opportunities of mechanosynthesis in green and scalable fabrication of metal–organic frameworks

“…HKUST-1 (Cu 3 (BTC) 2 ) is one of the wellstudied porous materials in a broad range of practical applications such as gas adsorption and separation or heterogeneous catalysis. [190][191][192][193] HKUST-1 is assembled from copper-based paddle wheel units connected together by trimesic acid. Pichon et al reported the quantitative formation of [Cu 3 (-BTC) 2 ]$xH 2 O through neat grinding of Cu(OAc) 2 $H 2 O and H 3 BTC for 20 min.…”