Porous Metal–Organic Frameworks for Carbon Dioxide Adsorption and Separation at Low Pressure

Abstract

The rapidly increasing concentration of CO2 in the atmosphere has resulted in a serious greenhouse effect. CO2 capture and storage (CSS) technology is widely accepted as an effective method for reduction of CO2 emissions. Metal–organic frameworks show an excellent potential for CO2 capture in CCS due to various advantages of high porosity, high surface area, adjustable pore structure, and multifunctionality. A series of works have been devoted to design of MOFs for CO2 capture and separation. Considering the low CO2 partial pressure in the practical industry, improving CO2 adsorption and separation performance at low pressure (including atmospheric pressure) is more meaningful. Establishing the structure–property relationships between MOFs and guest CO2 molecules is helpful for the design of MOFs as CO2 adsorbents. Therefore, we comprehensively review the factors which affect the CO2 capture performance on MOFs at low pressure, including pore structure, open metal sites, Lewis basic groups, and other polar groups. We further indicate the regulation of increasing CO2 uptake on modified MOFs through adsorption mechanisms based on clarified structures of MOFs. In addition, we discuss the strategies to improve separation performance of CO2 from flue gases, biogases, and crude C2H2 based on enhancement of CO2 uptake or sieving via porosity.

Metal Exchange Boosts the CO2 Selectivity of Metal Organic Frameworks Having Zn-Oxide Nodes

“…Ti, Ni, Cr, and V had the highest LC (1.40, 1.58, 2.07, and 2.33 e – for Ti, V, Cr, and Ni, respectively) among the M-HIFTOG02 series. Because CO 2 -MOF electrostatic interactions are important at low pressures, 53 high LCs of these metals led to enhanced CO 2 uptakes in these MOFs. Thus, at 0.1 bar, CO 2 uptakes of V-HIFTOG02 and Ni-HIFTOG02 even exceeded those of all IRMOFs.…”

Advances in Post‐Combustion CO2Capture by Physical Adsorption: From Materials Innovation to Separation Practice

“…Another method is introducing amine groups by post‐synthetic modification (PSM) [202] . PSM has been proven to be an effective approach to prepare advanced MOF adsorbents for efficient CO 2 capture [203] .…”

Recent progress in metal–organic framework/graphene-derived materials for energy storage and conversion: design, preparation, and application

“…Owing to the easily tunable chemical compositions of the organic linkers and metal nodes (metal ions/clusters), more than 20 000 different MOFs have been designed and synthesized in the past two decades. Their unique structures and properties make them potential candidates in many applications, such as environmental protection, 1-3 drug delivery, 4,5 gas adsorption and separation, [6][7][8][9] sensors, 10-12 catalysis, [13][14][15] electrochemical energy storage, [16][17][18][19][20][21] etc. Nevertheless, it should be noted that most pristine MOFs still suffer from the intrinsic drawbacks of low structural stability and poor electrical conductivity, which hinder their practical applications, especially in the eld of electrochemical energy storage and conversion.…”