Significantly Enhanced Carbon Dioxide Selective Adsorption via Gradual Acylamide Truncation in MOFs: Experimental and Theoretical Research

Abstract

A gradual amide truncation strategy was presented to tune the pore chemistry and CO2 capture performance of a series of tetracarboxylate-based Cu-MOFs. These MOFs exhibited a high density of Lewis basic sites (LBSs) and open metal sites and were prepared with the goal to enhance CO2 selective adsorption capacity. [Cu2(L1)(H2O)2] n (NJU-Bai42: NJU-Bai for Nanjing University Bai’s group), [Cu2(L2) (H2O)2] n (NJU-Bai17), and [Cu2(L3)(H2O)2] n (NTUniv-60: NTUniv for Nantong University) were synthesized, and we observed that the CO2 adsorption capacities and MOF structures were impacted by subtle changes in ligands. Interestingly, although the NTUniv-60 was decorated with the least LBSs in these three MOFs, its CO2 adsorption capacity reached 270 (53.0 wt %) and 164 (32.2 wt %) cm3 g–1 at 273 and 296 K under 1 bar, respectively, which is the highest data reported for MOFs under similar conditions. From the grand canonical Monte Carlo (GCMC) simulation, the cooperative interactions between the CO2 molecules within the shuttle-shaped cages of NTUniv-60 could potentially explain why the CO2 uptake is high in this material.

Optimized Pore Nanospace through the Construction of a Cagelike Metal–Organic Framework for CO2/N2 Separation

“…The increasingly serious greenhouse effect has led to a series of ecosystem environmental issues, such as melting glaciers, extreme weather, etc., due to past emissions of CO 2 mainly arising from fossil fuel combustion. − Carbon capture and sequestration (CCS) has been a promising technology for reducing the emissions of CO 2 to the atmosphere, thereby accomplishing carbon-neutral. − Conventional industrial CO 2 removal from the postcombustion flue gas is typically achieved by aqueous amine solutions; however, it usually involves some other issues, like equipment corrosion, intensive energy consumption, solvent distillation, and water use. − Therefore, developing a new CCS technology with environmentally friendly and energy-efficient features is of great importance. − …”

Expanding MOF with Unexpanded Channel via Ketone Decorated Ligand for Ethylene Purification and Stability Enhancement

“…The densely decorated ketone functional groups in the NTUniv-61 could dramatically change the inner environment of the channel, due to its recognition performance for polar molecules in previous literature . Abundant C–H···O hydrogen bonds could be found between the PDA 2– ligands in NTUniv-61 (Figure b and Figure c), the C–H···O distances were ca.…”

“…The densely decorated ketone functional groups in the NTUniv-61 could dramatically change the inner environment of the channel, due to its recognition performance for polar molecules in previous literature. 20 Gas Adsorptions and Separations Performance. In order to obtain the Brunauer−Emmett−Teller (BET) surface area data and channel properties of those two MOFs, we collected the 195 K CO 2 sorption isotherms using a dry ice− acetone bath.…”

“…We are interested in inserting new functional groups to boost MOFs performance . After our pioneering work of introducing alkynyl, amide, and piperazine into MOFs, the potential of those functional groups were further explored by us and other groups, producing NU-110 (the highest BET) and record-high C 2 H 2 , CH 4 , and CO 2 uptake data. To enrich our research and explore the potential of those functional groups, we planned to insert a functional group into some “C 2 H 6 first” MOFs to boost C2 separation ability.…”

Fine-Tuning MOFs with Amino Group for One-Step Ethylene Purification from the C2 Hydrocarbon Mixture

“…The idea of fine-tuning MOFs to boost performances was first reported by our group . Subsequently, record high C 2 H 2 , CH 4 , and CO 2 adsorption data were obtained by introducing more recognition sites for guest molecules. This method was also used by other groups for C2 separation ,, and CO 2 capture .…”