A heterogeneous cobalt-phosphonate network catalyst, [Co₂(2,2′-bipy)(H₄L)(H₂O)]H₂O (Co318), was synthesized by a hydrothermal reaction. The combination of Brønsted acid (–PO₃H₂) and Lewis acid (Co²⁺) sites makes Co318 an efficient catalyst for the conversion of saccharides to HMF. Under optimized conditions, glucose was quantitatively consumed and the yield of HMF was as high as 92%. Co318 was recycled four times without the loss of catalytic activity. When microcrystalline cellulose and regenerated cellulose were used, the yields of HMF were 33% and 50%, respectively, at 10 wt% catalyst loading. The yield of HMF increased to 59% when the loading of Co318 was increased to 40 wt%. GC-MS analysis confirmed that the reaction mixture contained both glucose and fructose intermediates, proving that the conversion of cellulose to HMF involved three steps: hydrolysis of cellulose to glucose, isomerization of glucose to fructose, and dehydration of fructose to HMF.

中文翻译：

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膦酸钴催化剂催化纤维素向5-羟甲基糠醛的高效转化

通过水热反应合成了多相膦酸钴网络催化剂[Co ₂（2,2'-bipy）（H ₄ L）（H ₂ O）] H ₂ O（Co318）。布朗斯台德酸（–PO ₃ H ₂）和路易斯酸（Co ²⁺）位点使Co318成为将糖类转化为HMF的有效催化剂。在最佳条件下，葡萄糖被定量消耗，HMF的产率高达92％。Co318循环了四次而没有失去催化活性。当使用微晶纤维素和再生纤维素时，在催化剂负载量为10重量％时，HMF的产率分别为33％和50％。当Co318的负载增加到40wt％时，HMF的产率增加到59％。GC-MS分析证实反应混合物同时包含葡萄糖和果糖中间体，证明纤维素向HMF的转化涉及三个步骤：纤维素水解为葡萄糖，葡萄糖异构化为果糖以及果糖脱水为HMF。