CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Haixi Institutes, Chinese Academy of Sciences (CAS), Fuzhou 350002, China.
College of Materials and Chemical Engineering, Hainan University, Haikou 570228, China.
Molecules. 2018 Feb 27;23(3):529. doi: 10.3390/molecules23030529.
Mesoporous ZSM-5 prepared by alkaline treatment was demonstrated as an efficient catalyst for the cellulose hydrolysis in ionic liquid (IL), affording a high yield of reducing sugar. It was demonstrated that mesoporous ZSM-5 (SiO₂/Al₂O₃ = 38) had 76.2% cellulose conversion and 49.6% yield of total reducing sugar (TRS). In comparison, the conventional ZSM-5 had a mere 41.3% cellulose conversion with 33.2% yield of TRS. The results indicated that the important role of mesopores in zeolites in elevating the TRS yield may be due to the diffusional alleviation of cellulose macromolecules. The effects of reaction time, temperature, and the ratio of catalyst to cellulose were investigated for optimal reaction conditions. It was found that IL could enter the inner channel of mesoporous ZSM-5 to promote the generation of H⁺ from Brönsted acid sites, which facilitated hydrolysis. Moreover, the mesoporous ZSM-5 showed excellent reusability for catalytic cycles by means of calcination of the used one, promising for its practical applications in the hydrolysis of cellulose.
通过碱性处理制备的中孔 ZSM-5 被证明是一种用于离子液体（IL）中纤维素水解的高效催化剂，可提供高收率的还原糖。结果表明，中孔 ZSM-5（SiO₂/Al₂O₃ = 38）的纤维素转化率为 76.2%，总还原糖（TRS）的收率为 49.6%。相比之下，传统 ZSM-5 的纤维素转化率仅为 41.3%，TRS 的收率为 33.2%。结果表明，中孔沸石中中孔在提高 TRS 收率方面的重要作用可能归因于纤维素大分子的扩散缓解。考察了反应时间、温度和催化剂与纤维素的比例等因素对最佳反应条件的影响。结果表明，IL 可以进入中孔 ZSM-5 的内通道，促进来自 Brönsted 酸位的 H⁺的生成，从而有利于水解。此外，通过煅烧用过的中孔 ZSM-5，其在催化循环中表现出优异的可重复使用性，有望在纤维素水解中实际应用。
