Synthesis and Characterization of Amorphous SiO2−FexOy Materials Starting from Iron Sulfate for Preliminary Studies of CO2 Adsorption
Abstract
:1. Introduction
2. Materials and Methods
2.1. Materials Synthesis
2.2. Materials Characterization
3. Results and Discussion
3.1. Material Characterization
3.1.1. XRD
3.1.2. FT-IR Spectroscopy
3.1.3. RAMAN Spectroscopy
3.1.4. Thermogravimetric Analysis
3.1.5. SEM (Scanning Electron Microscopy) Images
3.1.6. Energy Dispersive Spectroscopy (EDS)
3.1.7. N2 Adsorption Desorption Isotherms
3.2. Application, CO2 Adsorption Process
- The sample is heated in nitrogen at 150 °C for 30 min. This stage consists of cleaning the surface of the sample of organic impurities or ambient CO2 and bringing the sample to constant mass.
- The temperature is lowered to the desired adsorption temperature—in our case, 30 °C—and it is maintained for another 15 min in the N2 atmosphere.
- The adsorption stage lasts 90 min, during which the sample is exposed to a 30% CO2/N2 gas mixture (70 mL/min).
- After the end of the adsorption, the sample is kept in N2 for another 30 min to remove physically adsorbed CO2.
- The desorption process of chemosorbed CO2 on amine-grafted adsorbents takes place from 30 to 180 °C, with a heating rate of 10 °C/min and an isotherm of 30 min at 180 °C.
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Conflicts of Interest
References
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Sample Name | Surface Area, BET Method, m2/g | Pore Width, DFT Method, nm | Average Pore Diameter, nm | Total Pore Volume, cc/g | FHH Method, D |
---|---|---|---|---|---|
SiO2−FexOy | 38 | 5.09 | 10.03 | 0.0950 | 2.5942 |
SiO2−FexOy−Ce | 33 | 5.08 | 7.59 | 0.0618 | 2.6478 |
SiO2−FexOy−Li | 29 | 3.77 | 9.98 | 0.0733 | 2.5770 |
Sample Name | Surface Area, BET Method, m2/g | Pore Width, DFT Method, nm | Average Pore Diameter, nm | Total Pore Volume, cc/g | FHH Method, D |
---|---|---|---|---|---|
SiO2−FexOy−APTES | 12 | 3.67 | 5.26 | 0.0457 | 2.6731 |
SiO2−FexOy−Ce−APTES | 9 | 10.70 | 12.52 | 0.0092 | 2.5322 |
SiO2−FexOy−Li−APTES | 16 | 3.65 | 4.38 | 0.0593 | 2.6448 |
No. | Sample | Temp [ºC] | nCO2/g SiO2−FexOy [mmol/g SiO2-FexOy] | nCO2/nNH2 [mmol/mmol] |
---|---|---|---|---|
1. | SiO2−FexOy−APTES | 30 | 1.55 | 0.218 |
2. | SiO2−FexOy−Ce−APTES | 30 | 1.53 | 0.226 |
3. | SiO2−FexOy−Li−APTES | 30 | 1.58 | 0.260 |
Sample | Surface Area, m2/g | Adsorption Capacity (mmol/g) | References |
---|---|---|---|
Fibrous silica | 618 | 0.54 | [10] |
Ce-fibrous silica | 391 | 0.58 | [10] |
Silica monoliths | 760 | 0.52 | [62] |
Carbon monoliths | 1225 | 1.6 | [62] |
porous carbons from PET | 1690 | 1.31 | [63] |
CB-FM | 157 | ~1 | [64] |
Silica gels | 309 | 0.773 | [65] |
FS | 23.48 | 0.324 | [66] |
FSNM | 12.93 | 0.48 | [66] |
APTES_MCM-41 | 58.1 | 1.01 | [67] |
APTES_SBA-15 | 20.1 | 1.75 | [67] |
MCM-41/FeO | 1453 | 0.87 | [68] |
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Ianăşi, C.; Pascu, B.; Nemeş, N.; Popa, A. Synthesis and Characterization of Amorphous SiO2−FexOy Materials Starting from Iron Sulfate for Preliminary Studies of CO2 Adsorption. Separations 2023, 10, 352. https://doi.org/10.3390/separations10060352
Ianăşi C, Pascu B, Nemeş N, Popa A. Synthesis and Characterization of Amorphous SiO2−FexOy Materials Starting from Iron Sulfate for Preliminary Studies of CO2 Adsorption. Separations. 2023; 10(6):352. https://doi.org/10.3390/separations10060352
Chicago/Turabian StyleIanăşi, Cătălin, Bogdan Pascu, Nicoleta Nemeş, and Alexandru Popa. 2023. "Synthesis and Characterization of Amorphous SiO2−FexOy Materials Starting from Iron Sulfate for Preliminary Studies of CO2 Adsorption" Separations 10, no. 6: 352. https://doi.org/10.3390/separations10060352