2,5-Diformylfuran (DFF) is an attractive and challenging compound that can be synthesized with good selectivity by the oxidation of bio-based 5‐hydroxymethylfurfural (5-HMF) using specific catalysts. Vanadium-containing heteropoly acids (PMoV HPAs) are highly active oxidation catalysts whose activity can be tuned by changing vanadium(V) (V^V) content. This study reports the preparation of a number of PMoV HPAs with different V^V amount and type of outer-sphere cation and investigating their catalytic performance in 5-HMF-to-DFF conversion. The characterization of synthesized HPAs by simple instrumental methods (pH-measurement, potentiometry, and titration analysis) and NMR revealed retaining Keggin structure and increasing oxidation potential with rising V^V amount. The complete optimization of reaction conditions allowed one to reach a DFF yield of 92% using Co₂H₆P₃Mo₁₈V₇O₈₄ at 110 °C in water/MIBK for 90 min under atmospheric pressure. The described method of 5-HMF oxidation is based on using effective soft oxidants that can be easily recycled and reused at least five times without significant loss of catalytic activity.

2,5-二甲酰呋喃（DFF）是一种有吸引力且具有挑战性的化合物，可以通过使用特定的催化剂将生物基5-羟甲基糠醛（5-HMF）氧化而以良好的选择性合成。含钒杂多酸（PMoV HPA）是高活性的氧化催化剂，其活性可以通过改变钒（^V）的含量来调节。这项研究报告了许多具有不同V ^V量和外球阳离子类型的PMoV HPA的制备，并研究了它们在5-HMF到DFF转化中的催化性能。通过简单的仪器方法（pH测量，电位测定和滴定分析）和NMR对合成的HPA进行表征，结果表明保留Keggin结构并随着V ^V的升高而增加了氧化电势量。完全优化了反应条件，使用Co ₂ H ₆ P ₃ Mo ₁₈ V ₇ O ₈₄在110°C的水/ MIBK中于大气压下反应90分钟，可使DFF产率达到92％。所描述的5-HMF氧化方法基于使用有效的软氧化剂，该氧化剂可以容易地循环使用至少五次，而不会明显降低催化活性。