The non-toxic biologic material of expanded corn starch (ECS)-supported nitric acid (ECS-HNO₃ and ECS-NH₂-HNO₃) has been prepared via simple procedures. Both the materials are used as heterogeneous catalysts for the selective aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) with an up to 98% yield in γ-butyrolactone (GBL, a bio-based green solvent) containing as little as 10% (v/v) acetic acid (AcOH) after less than 5 h under ambient pressure of dioxygen at 50 ^oC. The ECS-NH₂-HNO₃ proved to be more stable than ECS-HNO₃ and was repeatedly used five times with almost no change in its catalytic performance.

膨化玉米淀粉（ECS）负载的硝酸（ECS-HNO ₃和ECS-NH ₂ -HNO ₃）的无毒生物材料已经通过简单的程序制备。两种材料均用作非均相催化剂，用于将5-羟甲基糠醛（HMF）有氧氧化为2,5-二甲酰呋喃（DFF），并在γ-丁内酯（GBL，一种基于生物的绿色溶剂）中产率高达98％。含有少至10％（v / v）乙酸在50下双氧环境压力小于5小时后乙酸（AcOH中）^ø ℃。ECS-NH ₂ -HNO ₃被证明是更稳定的比ECS-HNO ₃和重复使用五次，其催化性能几乎没有变化。