High and selective capture of low-concentration CO2 with an anion-functionalized ultramicroporous metal-organic framework

Abstract

CO 2 capture, especially under low-pressure range, is of significance to maintain long-duration human operation in confined spaces and decrease the CO 2 corrosion and freezing effect for the liquefaction of natural gas. Herein, we for the first time report a novel anion-functionalized ZU-16-Co (TIFSIX-3-Co, TIFSIX=hexafluorotitanate (TiF 6 2−), 3=pyrazine), which exhibits one-dimensional pore channels decorated by abundant F atoms, for efficient CO 2 capture at a concentration around 400-10,000 ppm. Among its isostructural MFSIX-3 (M=Si, Ti, Ge) family materials, ZU-16-Co with fine-tuned pore size of 3.62 Å exhibits the highest CO 2 uptake at 0.01 bar (10,000 ppm) and 1 bar (2.63 and 2.87 mmol g −1 , respectively). The high CO 2 capture ability of ZU-16-Co originates from the fine-tuned pore dimensions with strong F•••C=O host-guest interactions and relatively large pore volumes coming from its longer coordinated Ti-F-Co distance (3.9 Å) in c direction. The excellent carbon trapping performance was further verified by dynamic breakthrough tests for CO 2 /N 2 (1/99 and 15/85) and CO 2 /CH 4 (50/ 50) mixtures. The adsorption and separation performances, resulting from the fine-tuned pore system with periodic arrays of exposed functionalities, demonstrate that ultramicroporous ZU-16-Co can be a promising adsorbent for low-concentration carbon capture.

Research progress in metal–organic frameworks (MOFs) in CO2capture from post-combustion coal-fired flue gas: characteristics, preparation, modification and applications

“…Zhang et al 106 reported a novel anion-functionalized ZU16-Co (TIFSIX-3-Co) that could effectively capture CO 2 at a concentration of about 400–10 000 ppm. The CO 2 adsorption capacity at 298 K, 1 bar is 2.87 mmol g −1 , and the separation selectivity for CO 2 /N 2 (15/85) is 690.…”

Low-concentration CO2 capture using metal–organic frameworks – current status and future perspectives

“…The uptake capacity on the functionalized MOF was however slightly lower as compared to other high-performing MOFs such as TIFSIX-3-Ni (∼1.1 mmol g −1 at 298 K) 31 and ZU-16-Co (∼1.05 mmol g −1 at 298 K). 53 Correspondingly, the Δ H ads of the pyrazine-functionalized Co-MOF-74 was higher (−48.4 kJ mol −1 at zero loading) than other frameworks with highly tailored pore structures ( e.g. NbOFFIVE-1-Ni, −54.9 kJ mol −1 at 0.1 mmol g −1 CO 2 loading) 47 or chemisorption-based sorbents ( e.g.…”

Covalent organic frameworks (COFs): a promising CO2 capture candidate material

“…In particular, some MOFs with excellent performance are sensitive to water because of the weak bonding mode of coordination bonds, which greatly limits CO 2 capture by MOFs. 39,40…”