Selective Adsorption-Based Separation of Flue Gas and Natural Gas in Zirconium Metal-Organic Frameworks Nanocrystals

Abstract

Carbon capture from flue gas and natural gas offers a green path to construct a net-zero emissions economic system. Selective adsorption-based gas separation by employing metal-organic frameworks (MOFs) is regarded as a promising technology due to the advantages of simple processing, easy regeneration and high efficiency. We synthesized two Zirconium MOFs (UiO-66 and UiO-66-NH2) nanocrystals for selective capture and further removal of CO2 from flue gas and natural gas. In particular, UiO-66-NH2 nanocrystals have a smaller grain size, a large amount of defects, and pending –NH2 groups inside their pores which display effective CO2 selective adsorption abilities over CH4 and N2 with the theoretical separation factors of 20 and 7. This breakthrough experiment further verified the selective adsorption-based separation process of natural gas and flue gas. In one further step, we used the Monte Carlo simulation to investigate the optimized adsorption sites and energy of CO2, N2 and CH4 molecules in the gas mixture. The significantly large adsorption energy of CO2 (0.32 eV) over N2 (0.19 eV) and N2 (0.2 eV) may help us to reveal the selective adsorption mechanism.

Switching Xe/Kr adsorption selectivity in modified SBMOF-1: a theoretical study

“…The IGM (Independent Gradient Model) calculation 34 was performed to analyze the weak interaction between Kr/Xe and MOF with Multiwfn 35 coming from the calculations of Gaussian program. 36,37 To perform the energy decomposition analysis of the adsorption energy, the medium order symmetry-adapted perturbation theory (SAPT) calculations 38 were performed at the SAPT2/aug-cc-pVQZ-pp level of theory with PSI4 code 39 on the optimized geometries. Note that SAPT is essentially free of BSSE problem, 40 no additional correction for BSSE is needed.…”

“…To further understand the adsorption properties of Kr, Xe on SBMOF-1 and Mg-SBMOF-1, the adsorption sites, adsorption heats were explored, the weak interaction was analyzed with independent gradient model (IGM), and the energy decomposition analyses between MOF and Xe, Kr were also performed with SAPT. 36 At rst, the electronic structures of Xe and Kr adsorbed on SBMOF-1 were analyzed with density functional theory. From adsorption positions of Xe, Kr in the pore of SBMOF-1 as shown in the Fig.…”

Hard-and-Soft Integration Strategy for Preparation of Exceptionally Stable Zr(Hf)-UiO-66 via Thiol–Ene Click Chemistry

“…(a) CO 2 adsorption isotherms of Zr-UiO-66-SH and Zr-UiO-66-SH-h at 273 and 298 K. (b) Calculated isosteric heat values of CO 2 adsorption of Zr-UiO-66-SH and Zr-UiO-66-SH-h. (c) Virial plots of CO 2 adsorption on Zr-UiO-66-SH and Zr-UiO-66-SH-h. (d) Comparison of the CO 2 adsorption capacity and BET specific surface area of different reported UiO-66 samples at 273 K and 1 bar. ,,− …”

“…The introduction of the abovementioned functional groups not only reduced the specific surface area of the original UiO-66 but also interfered with the absorption of CO 2 . Adjusting function via Li atom, 40 −CH 3 , 44 and −NH 2 46 generates a positive effect on the absorption of CO 2 .…”

Sensing Properties of NH2-MIL-101 Series for Specific Amino Acids via Turn-On Fluorescence

“…MOFs are of high diversity in structures and properties, typically showing advantages of high porosity, high specific surface area, openly accessible functional sites, tunable pore size and high chemical/thermal stability [ 19 ]. Due to these superior features, MOFs have been successfully used in different areas including heterogeneous catalysis [ 20 ], gas adsorption and separation [ 21 , 22 ], chemical sensing [ 23 ], drug delivery [ 24 ], bioimaging [ 25 ], etc. As for the luminescent MOFs, the guest species introduced may interact with the backbones of MOFs and result in the enhancement or suppression of luminescence, thereby enabling the application of luminescent MOFs in chemical sensing [ 26 , 27 ].…”