Optimal Surface Amino-Functionalization Following Thermo-Alkaline Treatment of Nanostructured Silica Adsorbents for Enhanced CO2 Adsorption
| Autor: | Fernando Rojas-González, Obdulia Medina-Juárez, Isaac Kornhauser-Straus, Ulises Arellano-Sánchez, Miguel A. García-Sánchez |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Population 02 engineering and technology 010402 general chemistry 01 natural sciences lcsh:Technology Article CO2 enhanced capture SBA-15 habilitation for CO2 sorption desilication silanol functionalization covalent coordinated CO2 deposition chemistry.chemical_compound Adsorption Desorption Organic chemistry General Materials Science education lcsh:Microscopy lcsh:QC120-168.85 education.field_of_study lcsh:QH201-278.5 lcsh:T Mesoporous silica 021001 nanoscience & nanotechnology 0104 chemical sciences Amorphous solid Silanol chemistry Chemical engineering lcsh:TA1-2040 Selective adsorption Surface modification lcsh:Descriptive and experimental mechanics lcsh:Electrical engineering. Electronics. Nuclear engineering 0210 nano-technology lcsh:Engineering (General). Civil engineering (General) lcsh:TK1-9971 |
| Zdroj: | Materials, Vol 9, Iss 11, p 898 (2016) Materials Materials; Volume 9; Issue 11; Pages: 898 |
| ISSN: | 1996-1944 |
| Popis: | Special preparation of Santa Barbara Amorphous (SBA)-15, mesoporous silica with highly hexagonal ordered, these materials have been carried out for creating adsorbents exhibiting an enhanced and partially selective adsorption toward CO2. This creation starts from an adequate conditioning of the silica surface, via a thermo-alkaline treatment to increase the population of silanol species on it. CO2 adsorption is only reasonably achieved when the SiO2 surface becomes aminated after put in contact with a solution of an amino alkoxide compound in the right solvent. Unfunctionalized and amine-functionalized substrates were characterized through X-ray diffraction, N2 sorption, Raman spectroscopy, electron microscopy, 29Si solid-state Nuclear Magnetic Resonance (NMR), and NH3 thermal programmed desorption. These analyses proved that the thermo-alkaline procedure desilicates the substrate and eliminates the micropores (without affecting the SBA-15 capillaries), present in the original solid. NMR analysis confirms that the hydroxylated solid anchors more amino functionalizing molecules than the unhydroxylated material. The SBA-15 sample subjected to hydroxylation and amino-functionalization displays a high enthalpy of interaction, a reason why this solid is suitable for a strong deposition of CO2 but with the possibility of observing a low-pressure hysteresis phenomenon. Contrastingly, CH4 adsorption on amino-functionalized, hydroxylated SBA-15 substrates becomes almost five times lower than the CO2 one, thus giving proof of their selectivity toward CO2. Although the amount of retained CO2 is not yet similar to or higher than those determined in other investigations, the methodology herein described is still susceptible to optimization. |
| Databáze: | OpenAIRE |
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