https://doi.org/10.3390/molecules26247620
“4.1. Preparation of MOF-801
MOF-801 was synthesized according to a published route [29] by mixing ZrOCl2 (8H2O) (3.2 g, 10 mmol) and fumaric acid C4H4O4 (1.16 g, 10 mmol) in the presence of dimethylformamide DMF (40 mL). Formic acid (14 mL, 1M) used as a modulator was introduced in the mixture, which was stirred for 30 min at room temperature. The mixture was put in an ultrasonic bath (80 °C, 45 kHz, 90 W). After 30 min of reaction, a white precipitate was recovered by centrifugation and washed three times daily for 3 days with DMF, and three times daily for 3 days with ethanol. The solid was activated by drying for 24 h at two different temperatures (150 °C and 180 °C) under secondary vacuum.
4.2. Preparation of MIP-202
Measures of 1.15 g of ZrCl4 and 1.40 g of L-aspartic acid were mixed in 10 mL of water and placed in a sealed flask under autogen pressure in a silicon oil bath at 110 °C for 24 h. The obtained product was recovered by centrifugation and washed first with water and then with ethanol three times and dried under secondary vacuum at room temperature for 24 h [40].
4.3. Preparation of Muc-Zr MOF
Measures of 1.6 g of ZrCl4 and 0.975 g of trans, trans muconic acid with 576 µL of HCl as modulator, were mixed in 48 mL of DMF, and put in a small sealed flask in a silicon oil bath at 150 °C for 24 h under autogen pressure. The obtained product was recovered by centrifugation and washed three times with acetone.”
“Figure 7. Carbon dioxide adsorption isotherms at 298 K by the prepared MOFs. (Red) Muc-Zr MOF, (green) MOF-801, (blue) MIP-202; (top left) experimental data, (top right) predicted data. Experimental data reported as per square meter. (bottom left) Simulated data reported as per square meter (bottom right).” https://doi.org/10.3390/molecules26247620
“The carbon dioxide adsorption isotherms are presented in Figure 7. The shape of the sorption isotherms follows the same trends, regardless of the material studied. As expected, the CO2/MOF affinity is not very high, as denoted by the rather moderate slope at low relative pressure. Additionally, the inflexion of the curves, which also reflects this affinity, is not very marked. This is more especially true in the case of Muc-Zr MOF and MOF-801, which suggests that these materials weakly interact with carbon dioxide molecules. It can be noted that up to 20 kPa in the case of MOF-801 and Muc-Zr, the adsorbed amount increases in linear fashion versus the relative pressure. This is an indication that the surface appears as homogeneous for CO2 molecules. In contrast, in the case of MIP-202, there is a noticeable inflexion in the sorption isotherm located at p = 10 kPa. This inflexion can be interpreted as the change between two sorption regimes [53]. This shows the influence of high interaction sites (extra-framework anions (Cl−) and amine functions) as well as the impact of the framework on the CO2 adsorption mechanism.”