A water-stable fcu-MOF material with exposed amino groups for the multi-functional separation of small molecules

Abstract

The energy-efficient purification of methane from C 2-hydrocarbons is of great significance for the upgrading of natural gas. So does the capture of carbon dioxide for remission of greenhouse effect. It is well established that some functional sites, such as open metals sites, Lewis basic nitrogen sites and fluorine groups, have shown significantly enhanced affinity toward more polarizable molecules. Thus, a water-stable Eu 3+-based fcu-metal-organic framework (MOF) (compound 1) with amino functional groups has been successfully constructed through a reticular chemistry approach. As a result, the activated compound 1 exhibits moderately high uptakes of C 2-hydrocarbons, but a less obvious adsorption of CH 4 at the same conditions. Among them, the adsorption capacity of C 2 H 2 is up to 143.6 cm 3 cm −3 and a relatively high selectivity of C 2 H 2 /CH 4 (107.7) is obtained at near room temperature. Moreover, compound 1 is also validated as an exceptional adsorbent for CO 2 capture, with the fairly high capacity of CO 2 (92.6 cm 3 cm −3) and CO 2 /N 2 selectivity (151.7) at ambient conditions. The excellent performance of compound 1 is mainly driven by the exposed amino functional groups within the contracted pores. Such effect thus leads to the achievement of dual-functional platform for methane purification and carbon dioxide capture. Furthermore, compound 1 features a satisfactory water stability, which is confirmed by the powder X-ray diffraction (PXRD) analysis and the retest of porosity after being soaked in water.

Recent advances in the synthesis of monolithic metal-organic frameworks

“…Metal-organic frameworks (MOFs), which are selfassembled via coordination bonds between the metal ions or clusters and organic ligands, are emerging as a class of fascinating porous organic-inorganic hybrid crystal materials [1,2]. They exhibit fascinating physicochemical characteristics, including ultrahigh specific surface area, abundant active sites, permanent porosity, and diverse topological structure [3,4], making them potentially applicable in the fields of adsorption/separation, sensing, supercapacitors, drug delivery, functional peptidomics, and catalysis [5][6][7][8][9][10][11]. To date, majority of the reported MOFs are polydisperse microcrystalline powders.…”

Thermo-induced nanocomposites with improved catalytic efficiency for oxygen evolution

“…Therefore, exploring highly efficient OER catalysts is crucial for advancing the electrochemical water splitting reaction. Metal-organic frameworks (MOFs) are widely used in areas such as recognition [1][2][3], adsorption [4][5][6][7], and catalysis [8][9][10][11] because of their porous architecture and highly specific surface areas. Unfortunately, the low conductivity of MOFs has limited their applications in electrochemical processes.…”

Application of hierarchically porous metal-organic frameworks in heterogeneous catalysis: A review

“…MOFs possess exciting structures and unique physiochemical features such as ultra-high specific surface area, permanent nanoscale porosity, tunable pore environment, uniformly structured cavities, and abundant active sites [3,4]. As such, MOFs have been commonly utilized in adsorption or separation [5][6][7], catalysis [8,9], supercapacitors [10][11][12], and biomedicine [13,14]. Among these applications, heterogeneous catalysis is one of the earliest proven applications, and MOFs as catalysts have cemented an unparalleled status in this field [15].…”