A Bipyridyl Covalent Organic Framework with Coordinated Cu(I) for Membrane C₃H₆/C₃H₈ Separation

Abstract

Covalent organic frameworks (COFs) mixed matrix membranes (MMMs) combining individual attributes of COFs and polymers are promising for gas separation. However, applying COF MMMs for propylene/propane (C3H6/C3H8) separation remains a big challenge due to COF inert pores and C3H6/C3H8 similar molecular sizes. Herein, the designed synthesis of a Cu(I) coordinated COF for membrane C3H6/C3H8 separation is reported. A platform COF is synthesized from 5,5′‐diamino‐2,2′‐bipyridine and 2‐hydroxybenzene‐1,3,5‐tricarbaldehyde. This COF possesses a porous 2D structure with high crystallinity. Cu(I) is coordinated to bipyridyl moieties in the COF framework, acting as recognizable sites for C3H6 gas, as shown by the adsorption measurements. Cu(I) COF is blended with 6FDA‐DAM polymer to yield MMMs. This COF MMM exhibits selective and permeable separation of C3H6 from C3H8 (C3H6 permeability of 44.7 barrer, C3H6/C3H8 selectivity of 28.1). The high porosity and Cu(I) species contribute to the great improvement of separation performance by virtue of 2.3‐fold increase in permeability and 2.2‐fold increase in selectivity compared to pure 6FDA‐DAM. The superior performance to those of most relevant reported MMMs demonstrates that the Cu(I) coordinated COF is an excellent candidate material for C3H6 separation membranes.

Non-CO2 greenhouse gas separation using advanced porous materials

“…As a result, notable advancements have been achieved, surpassing the long-standing selectivity/permeability trade-off dilemma, especially in diverse gas mixture applications encompassing H 2 purification, 88,89 CO 2 capture, 90–93 and hydrocarbon separation. 94,95…”

Accelerated Diffusion of a Copper(I)-Functionalized COF Packed Bed Reactor for Efficient Continuous Flow Catalysis

“…Covalent organic frameworks (COFs), , as well-defined and predictable networks of building blocks linked by covalent bonds in a periodic arrangement, have drawn special attention from scientists, which have been widely employed in lots of cutting-edge fields including molecule separation, − heterogeneous catalysis, − energy storage, − and optoelectronics. − Although the immobilization of various metal catalysts on COFs for efficient catalysis under batch conditions has been reported, − there are few examples of effective heterogeneous catalysis using COF materials as catalyst supports in continuous flow processes. Due to the superiority of accurate control over the frame structures and the types of functional groups to support the catalysts, we believe that the COFs with large specific surfaces also possess the potential to be used as packed bed fillers for efficient continuous catalysis.…”

Porous organic framework membranes based on interface-induced polymerisation: design, synthesis and applications

“…16 Initially, researchers mostly prepared mixed matrix membranes by blending POF powders with polymers, but the wide distribution of dopant particles made it difficult to regularise the formation of membranes, leading to internal inhomogeneity or even physical defects in the composite membrane. 17,18 Subsequently, the vacuum-assisted ltration method was developed by layer-bylayer stacking of the nanosheets to form membranes, where the formation of discontinuous channels was inevitable if the layers were not tightly linked. 19 Recently, interface polymerisation has become an effective way for the preparation of continuous pure-phase POF membranes.…”