纤维二糖与葡萄糖催化转化制备乙二醇

摘要

选用纤维二糖作为探针分子，探索纤维素催化转化制备乙二醇过程的反应路径。分别考察了纤维二糖和葡萄糖在双组分催化剂H2WO4和Ru/C下的催化反应活性。结果表明，乙二醇不仅来自于纤维二糖水解产物葡萄糖的逆羟醛缩合作用，同时也可以来自于纤维二糖的直接逆羟醛缩合过程。而且，纤维二糖的直接逆羟醛缩合作用对糖苷键的水解也有一定的促进作用。比较发现，钨基催化剂作用下纤维二糖的逆羟醛缩合反应活性比葡萄糖要低，因此乙醇醛可以缓慢产生并在Ru/C催化剂上迅速加氢生成乙二醇。使得以纤维二糖作为原料比以葡萄糖作为原料时获得更高的乙二醇收率。%Cellobiose was used as a model feedstock to probe the reaction pathways of cellulose to ethylene glycol (EG). Its reactivity was compared with that of glucose using a catalyst composed of H2WO4 and Ru/C. EG can be produced by both the direct retro-aldol condensation of cellobiose and the retro-aldol condensation of glucose derived from cellobiose hydrolysis. The direct retro-aldol con-densation of cellobiose further promoted the hydrolysis of cellobiose. Cellobiose has a lower reac-tivity for retro-aldol condensation than glucose, which decreased the formation rate of glycolalde-hyde and made it more matched with the subsequent hydrogenation rate, thus leading to increased yield of EG from cellobiose.