Wang Yaxu, Chai Jiaxuan, Li Yining, Ma Zichuan
Hebei Key Laboratory of Inorganic Nano-Materials, College of Chemistry and Material Sciences, Hebei Normal University, Shijiazhuang 050024, China.
Molecules. 2025 Feb 26;30(5):1073. doi: 10.3390/molecules30051073.
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]-SOH and the ion-paired (IP) state AlO:OSOH. 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 -xylene, extending the reaction temperature range to 110-190 °C and increasing the breakthrough adsorption capacity () to 946.1 mg g. However, excessive aluminum ion incorporation was detrimental to the adsorption performance of SAs for -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.
采用溶胶-凝胶法合成了一组具有不同铝硅比（S-x）的二氧化硅基载体，随后用氯磺酸进行改性，制备出负载型磺酸（SA-x）。通过傅里叶变换红外光谱（FTIR）、比表面积测定（BET）和高效液相色谱-质谱联用（HPLC-MS）等技术对S-x和SA-x材料及其吸附产物进行了表征。分析表明，SA-x材料中的磺酸基团以两种锚定状态存在：共价键合（CB）状态[SiOx-O]-SOH和离子对（IP）状态AlO:OSOH。CB态磺酸的磺化反应活性增强，而IP态磺酸的磺化反应活性减弱。引入少量铝离子（x = 0.1）显著提高了磺酸对二甲苯的吸附效率，将反应温度范围扩展至110-190℃，并将穿透吸附容量提高至946.1 mg/g。然而，过量引入铝离子不利于磺酸对二甲苯的吸附性能。SA-0.1表现出优异的吸附能力和良好的可回收性，在连续四个吸附/再生循环中保持其性能，仅有4.5%的轻微下降。这些研究结果表明，用少量铝离子制备的磺酸作为去除苯系污染物的吸附剂具有巨大的应用潜力。
