Influence of Aluminum Incorporation on the Adsorptive Performance of Silica-Based Supported Sulfonic Acid for the Chemical Recovery of Gaseous <i>O</i>-Xylene
A group of silica-based supports with varying Al/Si ratios (S−x) was synthesized using the sol–gel method, followed by a chlorosulfonic acid modification to produce supported sulfonic acids (SA−x). The S−x and SA−x materials, along with their adsorption products, were characterized via techniques su...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-02-01
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| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/30/5/1073 |
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| Summary: | A group of silica-based supports with varying Al/Si ratios (S−x) was synthesized using the sol–gel method, followed by a chlorosulfonic acid modification to produce supported sulfonic acids (SA−x). The S−x and SA−x materials, along with their adsorption products, were characterized via techniques such as FTIR, BET, and HPLC-MS. The analysis revealed that the sulfonic acid groups in the SA−x materials existed in two anchoring states: the covalently bonded (CB) state [SiOx–O]<sup>ɗ−</sup>–SO<sub>3</sub>H<sup>ɗ+</sup> and the ion-paired (IP) state AlO<sub>y</sub><sup>+</sup>:OSO<sub>3</sub>H<sup>−</sup>. The sulfonation reactivity of the CB-state sulfonic acid was enhanced, whereas that of the IP-state counterpart was diminished. The incorporation of a minor quantity of aluminum ions (x = 0.1) markedly enhanced the adsorption efficiency of SAs for <i>o</i>-xylene, extending the reaction temperature range to 110–190 °C and increasing the breakthrough adsorption capacity (<i>Q</i><sub>B</sub>) to 946.1 mg g<sup>−1</sup>. However, excessive aluminum ion incorporation was detrimental to the adsorption performance of SAs for <i>o</i>-xylene. SA−0.1 showed superior adsorptive capabilities and excellent recyclability, maintaining its performance over four consecutive adsorption/regeneration cycles with only a minor decrease of 4.5%. These findings suggest that SAs prepared with a minor amount of aluminum ions have significant potential for application as adsorbents for the removal of benzene series pollutants. |
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| ISSN: | 1420-3049 |