Efficient adsorption of ammonia by incorporation of metal ionic liquids into silica gels as mesoporous composites
| Autor: | Shaojuan Zeng, Junli Wang, Pengfei Li, Hui Wang, Xiangping Zhang, Haifeng Dong, Xiaochun Zhang |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Silica gel General Chemical Engineering chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Industrial and Manufacturing Engineering 0104 chemical sciences Metal chemistry.chemical_compound Adsorption chemistry visual_art Ionic liquid visual_art.visual_art_medium Environmental Chemistry Gas separation Composite material 0210 nano-technology Selectivity Mesoporous material Cobalt |
| Zdroj: | Chemical Engineering Journal. 370:81-88 |
| ISSN: | 1385-8947 |
| Popis: | The emerging of ionic liquids (ILs) provides a promising way to efficiently separate ammonia (NH3) and simultaneously recover NH3 due to their negligible volatility, good affinity with NH3 and designable structures. However, the relatively high viscosities of ILs and the limited gas-liquid interface severely affect gas diffusion in ILs, which hinders their practical use in industries. In this work, in order to overcome the mass-transfer limitations of ILs in gas separation, three metal ILs (MILs), [Bmim]2[CuCl4], [Bmim]2[NiCl4] and [Bmim]2[Co(NCS)4], with good affinity toward NH3 were incorporated into porous silica gels with large surface area and abundant hydroxyl groups, by an impregnation-vaporization method to form novel MIL@silica gel composites for rapid, efficient and reversible adsorption of NH3. The FT-IR and BET results indicated that the prepared adsorbents with different loadings of MILs are mesoporous composites. The [Bmim]2[Co(NCS)4]@silica gel composites not only show much higher NH3 capacity and NH3 selectivity than pristine silica gel and faster adsorption rate than the corresponding pure MILs, but also exhibit excellent reversibility. The highest capacity of NH3 adsorption up to 99.808 mg NH3·(g adsorbent)−1 in 15 min was obtained when the loading of [Bmim]2[Co(NCS)4] in the MIL@silica gel composite was 48.89 wt%, which could be attributed to the synergistic interaction of the complexation and hydrogen bonding between cobalt coordinated anion and NH3 as well as mesoporous structures. Moreover, the NH3 absorbed by the [Bmim]2[Co(SCN)4]@silica gel can be completely released in 15 min, and no obvious losses in NH3 capacity were detected during five adsorption and regeneration cycles, indicating great potentials as adsorbents for NH3 separation applications. |
| Databáze: | OpenAIRE |
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