State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, Discipline of Industrial Catalysis, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
Zhijiang College, Zhejiang University of Technology, Shaoxing 312030, China.
Molecules. 2022 May 14;27(10):3149. doi: 10.3390/molecules27103149.
Vermiculite is a natural mineral. In this study, vermiculite and acid-activated vermiculite was used as a solid acid catalyst for the hydrolysis of cellulose in water. The catalysts were characterized by XRD, FT-IR, and BET. The effects of time, temperature, mass ratio and water amount on the reaction were investigated in the batch reactor. The results showed that the highest total reducing sugars (TRS) yield of 40.1% could be obtained on the vermiculite activated by 35 (wt)% HSO with the mass ratio of catalyst to cellulose of 0.18 and water to cellulose of 16 at 478 K for 3.5 h. The acid-activated vermiculite was a stable catalyst through calcination at 628 K and the yield of TRS decreased to 36.2% after three times reuse. The results showed that the crystal structure of vermiculite was destroyed and the surface -OH groups increased after the acid treatment. However, the synergistic effect of a strongly electrostatic polarization and Brönsted acid was responsible for the efficient conversion of cellulose. The mechanism of cellulose hydrolysis on the acid-activated vermiculite was suggested. This work provides a promising strategy to design an efficient solid catalyst for the cellulose hydrolysis, and expands the use of vermiculite in a new field.
蛭石是一种天然矿物。在这项研究中，蛭石和酸活化蛭石被用作纤维素在水中水解的固体酸催化剂。通过 XRD、FT-IR 和 BET 对催化剂进行了表征。在间歇式反应器中考察了时间、温度、质量比和水量对反应的影响。结果表明，在 478 K 下反应 3.5 h，用 35（wt）% H 2 SO 4 活化的蛭石，催化剂与纤维素的质量比为 0.18，水与纤维素的质量比为 16 时，总还原糖（TRS）的最高收率可达 40.1%。经 628 K 煅烧后，酸活化蛭石是一种稳定的催化剂，三次重复使用后 TRS 的收率下降至 36.2%。结果表明，酸处理后蛭石的晶体结构被破坏，表面-OH 基团增加。然而，强静电极化和 Brönsted 酸的协同作用是纤维素高效转化的原因。提出了纤维素在酸活化蛭石上水解的机理。这项工作为设计纤维素水解的高效固体催化剂提供了一种有前景的策略，并将蛭石在新领域的应用扩展。
