基于固体酸的纤维素非均相催化糖化的研究进展

Heterogeneous saccharification of cellulose by solid acid

作为纤维素水解产物,葡萄糖可进一步反应产生果糖、山梨醇、糠醛、乙酰丙酸等重要能源物质和基础平台化合物,因此高效催化纤维素定向转化为葡萄糖对获得高附加值化学品具有重要意义。本文从催化剂的物理化学结构与催化性能之间相互影响关系的角度,综述了磺化固体酸、氢型沸石、金属氧化物、负载金属和杂多酸5种主要非均相催化剂近年来的研究进展及未来的发展方向,分析得出以上催化剂具备易于与水解产物分离、高回收率、稳定的催化活性以及环境友好等明显优势,但仍存在与纤维素接触困难、活性组分容易损失等问题,指出通过引入活性官能团使催化剂兼有纤维素吸附、溶解和水解能力及利用官能团内部作用或固载使催化剂减少组分损失是纤维素非均相催化剂的发展方向。

As the main hydrolysate of cellulose,glucose is able to form a variety of important energy materials and valuable platform chemicals,such as fructose,sorbitol,furfural,and levulinic acid, through isomerization,dehydration,rehydration,hydrogenation,hydrogenolysis or other further reactions. Therefore,it is of great significance for the production of high additional value products by transforming cellulose into glucose,a crucial intermediate,with both high efficiency and excellent selectivity. This article is aimed to review ongoing research progress and to preview the future trends of five predominant types of heterogeneous catalysts,including sulfonated solid acid,H-type zeolite, metal oxide,supported metal and heteropolyacid,in the hydrolytic reaction of cellulose from the perspective of the interaction between the physical and chemical structures of the catalysts and their catalytic activity. The catalysts mentioned above have evident advantages in the ease of separation from products,recyclability,reusability,stability of catalytic activity and environmental influence,but still need improvement in cellulose contact and active components retainment. In the future,it shall be focused on enabling heterogeneous catalysts to absorb,dissolving and hydrolyzing cellulose through functional groups and stabilizing their active components through inner interactions of functional groups or immobilization.