A series of protonated molybdenum trioxide and nitrogen-doped carbon (Mo-HNC) were prepared through a facile method and applied as a bifunctional catalyst for the direct synthesis of 2,5-diformylfuran (DFF) from fructose. The molybdenum trioxide loading amount is a key factor either for the synthesis of the catalyst or for the catalytic performance in fructose to DFF transformation. Higher MoO₃ loading contributes to higher surface area, and the higher surface area will in turn promote the protonation process, resulting in higher acid density for the catalysts. The catalysts showed good activity in both the dehydration of fructose to HMF and the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to DFF. Under optimized reaction conditions, DFF yield of 77% could be achieved in 9 h at 150 °C. In addition, the Mo-HNC catalyst can be easily separated from the reaction solution and reused without significant loss in activity. Thus, this research provided an efficient method for the transformation of fructose to DFF in tandem reactions of dehydration and oxidation.

中文翻译：

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含MoO _3的质子化氮掺杂碳作为双功能催化剂，可从果糖一步合成2,5-二甲酰呋喃

通过一种简便的方法制备了一系列质子化的三氧化钼和氮掺杂的碳（Mo-HNC），并将其用作双功能催化剂，用于从果糖直接合成2,5-二甲酰呋喃（DFF）。三氧化钼的负载量是催化剂合成或果糖向DFF转化的催化性能的关键因素。较高的MoO ₃负载有助于更大的表面积，而更大的表面积又将促进质子化过程，从而导致催化剂的更高的酸密度。该催化剂在果糖脱水成HMF和5-羟甲基糠醛（HMF）有氧氧化成DFF方面均显示出良好的活性。在优化的反应条件下，在150°C的9小时内DFF的收率可达到77％。另外，可以容易地将Mo-HNC催化剂从反应溶液中分离并重复使用，而没有明显的活性损失。因此，本研究提供了一种在脱水和氧化串联反应中将果糖转化为DFF的有效方法。