Efficient Adsorption of Acetylene over CO₂ in Bioinspired Covalent Organic Frameworks

Abstract

Rational design of covalent organic frameworks (COFs) to broaden their diversity is highly desirable but challenging due to the limited, expensive, and complex building blocks, especially compared with other easily available porous materials. In this work, we fabricated two novel bioinspired COFs, namely, NUS-71 and NUS-72, using reticular chemistry with ellagic acid and triboronic acid-based building blocks. Both COFs with AB stacking mode exhibit high acetylene (C2H2) adsorption capacity and excellent separation performance for C2H2/CO2 mixtures, which is significant but rarely explored using COFs. The impressive affinities for C2H2 appear to be related to the sandwich structure formed by C2H2 and the host framework via multiple host–guest interactions. This work not only represents a new avenue for the construction of low-cost COFs but also expands the variety of the COF family using natural biochemicals as building blocks for broad application.

Dative B←N bonds based crystalline organic framework with permanent porosity for acetylene storage and separation

“…Based on the working capacity, 1 kg BNOF-1 could adsorb 12.5 L C2H2 in BNOF-1 and directly produce 4.0 L CO2 with high purity (> 99.0 %). The yield of C2H2 is higher than that of NKCOF-12 (10.04 L), 58 but lower than COF materials NUS-71 (31.4 L) 62 and NUS-72 (35.8 L), 62 as well as several benchmark MOFs for C2H2/CO2 separation supported by open metal sites and/or polar functional groups, such as TIFSIX-2-Cu-i (73.9 L), 69 FJU-90 (41.9 L), 70 CPL-1-NH2 (30.9 L), 71 and UTSA-300 (17.2 L). 72 The dynamic separation ratio can be determined to be 3.1, which is consistent with the IAST selectivity (3.2) and surpasses the values in some MOFs like FJU-22 (1.9), 68 SNNU-45 (2.9), 73 and NKMOF-1-Ni (2.6).…”

“…3f and S6–S9†). Under ambient conditions, BNOF-1 exhibits the highest volumetric adsorption capacity for C 2 H 2 and CO 2 (113.2, 75.2 cm 3 g −1 ) as compared to the reported COF materials, such as NKCOF-12 (78, 55 cm 3 g −1 ), 58 2D sql COF (77.8, 39.4 cm 3 g −1 ), 59 3D pts COF (71.4, 32 cm 3 g −1 ), 59 TpPa-NO 2 (63.73, 45.18 cm 3 g −1 ), 60 PAF-120 (50.8, 30 cm 3 g −1 ), 61 NUS-72 (48, 11.2 cm 3 g −1 ), 62 NUS-71 (42.4, 10.3 cm 3 g −1 ), 62 ZJUT-2 (36, 20.7 cm 3 g −1 ), 63 ZJUT-3 (34.7, 16.1 cm 3 g −1 ), 63 et al (Fig. 3c and Table S1†), which could be a new benchmark organic framework for C 2 H 2 and CO 2 storage.…”

Well‐Defined Conjugated Reticular Oligomer “Blood Cells” and Conducting Polymer “Neurons” Constructing “Muscle”‐Biomimetic Electrocatalysts for Water Electrolysis

“…Covalent organic frameworks (COFs), a burgeoning kind of crystalline porous organic polymer, have the following favorable characteristics: highly aligned structure, permanent porosity, functional diversity. [ 1,2 ] These characteristics, together with the extended intralayer π conjugation and columnar π arrays endow COFs with a wide array of applications, such as: gas adsorption/separation, [ 3,4 ] heterogeneous catalysis, [ 5,6 ] photoelectric device, [ 7,8 ] as well as energy conversion and storage. [ 9,10 ] Recently, COFs have attracted extensive research interest in the field of water electrolysis due to their directional structure and modularizable nature.…”

Rationally Fabricating Three-Dimensional Covalent Organic Frameworks for Propyne/Propylene Separation

“…As an emerging class of crystalline porous materials, covalent organic frameworks (COFs) are mainly constructed from light elements (e.g., C, H, O, and N) through covalent bonds. , Their attractive features, such as low skeleton density, a high specific surface area, high porosity, and a nonpolar pore environment, make COFs great candidates for gas separation applications. , For example, in 2018, the Zhu group synthesized the first two-dimensional (2D) naphthalene diimide COF (PAF-110) capable of selective separation of C 2 H 2 from C 2 H 4 at ambient temperatures . Recently, our group designed and synthesized a series of three-dimensional (3D) COFs with bcu topology, which could be used to efficiently separate C 2 H 6 from C 2 H 4 .…”