Vanadium (V)-containing all-silica beta-zeolites (VSi-Beta) were directly synthesized using a dry-gel-conversion route, in which the gel was prepared from the acid-catalysed co-hydrolysis of a silica precursor and ammonium metavanadate. Besides the framework isolated V species, VSi-Beta contained tetrahedral [V₂O₇]⁴⁻ and (VO₃)_nⁿ⁻ species that were bonded to the framework with a high dispersion. These V species resisted the over-oxidation of fructose and efficiently catalyzed the oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF). As a result, VSi-Beta demonstrated high activity in the one-pot and one-step conversion of fructose into DFF using atmospheric oxygen (O₂) in the presence of sulfuric acid, affording a high yield of 86.3% and a maximum turnover number (TON) of 270. The catalyst can be easily recovered by filtration and exhibits good reusability. Various other carbohydrates (glucose, sucrose, inulin, raffinose, maltose and starch) were also effectively converted into DFF using VSi-Beta.

中文翻译：

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直接合成含V的全硅β-沸石，可将碳水化合物有效地一锅一步转化为2,5-二甲酰呋喃

使用干凝胶转化途径直接合成含钒（V）的全硅β-沸石（VSi-Beta），其中凝胶是由二氧化硅前驱体和偏钒酸铵的酸催化共水解制得的。除了框架分离V族物质，VSI-β包含四面体[V ₂ ö ₇ ] ^4-和（VO ₃）_ñ ^{ñ -}与骨架高度分散地结合的物种。这些V物种抵抗果糖的过氧化，并有效催化5-羟甲基糠醛（HMF）氧化为2,5-二甲酰呋喃（DFF）。结果，VSi-Beta在硫酸存在下使用大气氧气（O ₂）将果糖一锅一步转化为DFF表现出高活性，可提供86.3％的高收率和最大周转率（TON）为270。该催化剂可以容易地通过过滤回收并且显示出良好的可重复使用性。还使用VSi-Beta将各种其他碳水化合物（葡萄糖，蔗糖，菊粉，棉子糖，麦芽糖和淀粉）有效地转化为DFF。