Synthesis, Characterizations, and Adsorption Isotherms of CO2 on Chromium Terephthalate (MIL-101) Metal-organic Frameworks (Mofs)

Abstract

The concentration of CO2 in the atmosphere caused by fossil fuels, power plants, and transportation is the most significant environmental issue in the world today. Intensive efforts have been made to minimize CO2 levels to reduce global warming. Metal-organic frameworks (MOFs), crystalline porous materials, exhibit great potential to adsorb carbon dioxide. In the present study, research was conducted on the synthesis, characterization, and adsorption isotherms of MIL-101. MIL-101, one type of mesoporous MOF, can adsorb enormous amounts of CO2. The synthesis was carried out using a fluorine-free hydrothermal reaction method. The porous properties, structure, morphology, thermal stability, and chemical functionalities of MIL-101 Cr were measured by N2 adsorption/desorption isotherms, X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. The volumetric uptakes of CO2 were experimentally measured at temperatures of 298-308 K and pressure of up to 600 kPa. The experimental result was correlated with the Toth isotherm model, showing the heterogeneity of the adsorbent. The heat of adsorption of MIL-101 was determined from the measured isotherm data, indicating the strength between the adsorbent and adsorbate molecule.

Synthesis of Cu-BTC Metal-Organic Framework for CO2 Capture via Solvent-free Method: Effect of Metal Precursor and Molar Ratio

“…8, the higher the surface area and pore volume of Cu-BTC, the higher the CO2 adsorption capacity achieved and vice versa. The observed trend was in line with the findings of other reported works (Chen et al, 2018;Nobar, 2018;Yulia et al, 2019). Moreover, the textural properties of Cu-BTC synthesized in this work were found to be in line with the result of CO2 adsorption capacity.…”

Elucidating Improvements to MIL‐101(Cr)’s Porosity and Particle Size Distributions based on Innovations and Fine‐Tuning in Synthesis Procedures

“…[ 66 ] On the other hand, HNO 3 ‐MIL‐101(Cr) has reaction mixtures with molar ratios of Cr:H 2 BDC:HNO 3 :H 2 O = 1:1:1:277 [ 12,69,73,88 ] or 1:1:1:265. [ 18,31,72 ] The reaction conditions for HCl‐MIL‐101(Cr) and HNO 3 ‐MIL‐101(Cr) bear close semblance to the HF‐based syntheses at 200–220 °C for 8, [ 12,17,18,55,62,70,72,74 ] 10, [ 59,65,82 ] 12, [ 57,60,64,66,71 ] or even 15 h. [ 68,81,86,87 ] Reports suggest that using HCl instead of HF reduces the MIL‐101(Cr) particle sizes (e.g., decreasing from 500–1500 to 200–1200 nm) [ 17 ] whereas replacing HF with HNO 3 seems to increase MIL‐101(Cr) crystallite sizes (e.g., increasing from 560–1100 to 720–1490 nm). [ 31,69 ] Specifically, by lowering the pH of the reaction mixture, HNO 3 reduces the crystal nucleation speeds to form larger crystallites.…”

“…[11] Although HCl is a stronger acid than HNO 3 , H 2 SO 4 , and HF (Table 3), MIL-101(Cr) synthesized using HCl (denoted HCl-MIL-101(Cr)) in molar ratios such as 1 Cr:1 H 2 BDC:1 HCl:266 H 2 O remains highly crystalline. [17,57,60,64,65] Nonetheless, high concentrations of electronegative chloride (Cl − ) ions can cause defects in MIL-101(Cr) and alter nucleation speeds. [66] On the other hand, HNO 3 -MIL-101(Cr) has reaction mixtures with molar ratios of Cr:H 2 BDC:HNO 3 :H 2 O = 1:1:1:277 [12,69,73,88] or 1:1:1:265.…”

Gamma Irradiation of Cellulose Acetate-Polyethylene Glycol 400 Composite Membrane and Its Performance Test for Gas Separation

“…Various types of technologies that can be applied for CO2 gas separation have been investigated by many researchers, one of which is membrane technology (Kartohardjono et al, 2017;Kusrini et al, 2018;Yulia et al, 2019). Membrane separation technology was reported to have advantages, such as being environmentally friendly, having relatively low operating costs and low mobility, only requiring a compact space, and ease of maintenance and operation (Bandehali et al, 2020).…”