Mesoporous activated carbon from sunflower shells (SAC) modified with sulfonic acid groups (SACSO₃H-XX) was synthesized by grafting the sulfonic groups on the carbon surface to produce novel heterogeneous and reusable solid acid catalysts.

The mesoporous carbon was prepared by chemical (H₃PO₄) and thermal (600 °C) activation of sunflower seed shells. Four materials with increasing SO₃H content (SACSO₃H-5, SACSO₃H-10, SACSO₃H-15, and SACSO₃H-20) were obtained using rising chlorosulfonic acid:SAC ratios. They were texturally and physicochemically characterized by SEM-EDX, BET, FT-IR, and TGA-DSC. Potentiometric titration with n-butylamine technique was used to evaluate their acidic properties. The results showed that both the acid strength and the number of acid sites increased with the SO₃H content in the SACSO₃H-XX samples. The FT-IR spectra of SACSO₃H-XX samples confirmed the successful functionalization of SAC with the sulfonic acid group. TGA-DSC diagrams of SACSO₃H-20 showed that the elimination of the sulfonic groups takes place in the range 250–350 °C.

The activity and selectivity of SACSO₃H-XX in the esterification reaction of itaconic acid with absolute ethanol to form the diester derivative depended strongly on their acidic properties. Furthermore, the effective separation of the product combined with the use of a recyclable catalyst resulted in a clean and environmentally friendly strategy for the synthesis of diethyl itaconate, a bioproduct of relevance to the biorefinery industry.

通过将磺酸基团接枝到碳表面上以产生新型的非均相和可重复使用的固体酸催化剂，合成了被磺酸基团修饰的向日葵壳（SAC）的中孔活性炭（SACSO ₃ H-XX）。

中孔碳是通过化学（H ₃ PO ₄）和热（600°C）活化葵花籽壳而制备的。使用增加的氯磺酸：SAC比率获得了四种具有增加的SO ₃ H含量的材料（SACSO ₃ H-5，SACSO ₃ H-10，SACSO ₃ H-15和SACSO ₃ H-20）。通过SEM-EDX，BET，FT-IR和TGA-DSC在结构上和物理化学上对它们进行了表征。用正丁胺技术进行电位滴定来评估其酸性。结果表明，随着SACSO _3中SO ₃ H含量的增加，酸强度和酸位点数量均增加。H-XX样本。SACSO ₃ H-XX样品的FT-IR光谱证实了SAC具有磺酸基的成功官能化。SACSO ₃ H-20的TGA-DSC图表明，磺酸基的消除发生在250-350°C的范围内。

在衣康酸与无水乙醇形成二酯衍生物的酯化反应中，SACSO ₃ H-XX的活性和选择性很大程度上取决于它们的酸性。此外，产物的有效分离与使用可循环利用的催化剂相结合，导致了合成衣康酸二乙酯的清洁，环保的策略，衣康酸二乙酯是与生物精炼工业相关的生物产物。