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]