Hβ分子筛催化甜高粱秆汁转化制呋喃类化合物

以γ-丁内酯为溶剂，研究了Hβ分子筛催化富含蔗糖、葡萄糖和果糖的甜高粱秆汁转化制呋喃类化合物（5-羟甲基糠醛或糠醛）的性能。结果表明，甜高粱秆汁在Hβ分子筛上主要转化为5-羟甲基糠醛，而含糖量相同的模型甜高粱秆汁在相同的反应条件下，主要产物却是糠醛。²⁷Al 固体核磁结果表明，甜高粱秆汁中的微量碱性金属钾等能与Hβ分子筛发生离子交换，导致Hβ分子筛上六配位铝转变为四配位铝；因为六碳糖生成糠醛需要Hβ分子筛上具备合适的铝配位环境，而离子交换引起铝配位状态的变化，导致了甜高粱秆汁在Hβ分子筛上的主要产物是5-羟甲基糠醛。

Catalytic conversion of sweet sorghum stalk juice to furan compounds over Hβ zeolite

The conversion of sweet sorghum stalk juice rich in sucrose, glucose and fructose to furan compounds (5-hydroxymethylfurfural or furfural) was investigated over Hβ zeolite in γ-butyrolactone solvent. The results indicated that the main product for the conversion of sweet sorghum stalk juice (SSSJ) was 5-hydroxymethylfurfural; however, high yield of furfural was obtained in the conversion of model sweet sorghum stalk juice (MSSSJ) containing the same amount of hexose under the same conditions. The ²⁷Al MAS NMR results showed that ion-exchange took place between the Hβ zeolite and alkaline ions (mainly potassium) in the sweet sorghum stalk juice, resulting in the transformation of octahedrally coordinated aluminum into tetrahedrally coordinated framework aluminum. As an appropriate configuration environment of aluminum for Hβ was necessary for the formation of furfural from hexose, high yield of 5-hydroxymethylfurfural was achieved for the conversion of sweet sorghum stalk juice (SSSJ) due to the ion-exchange of Hβ with alkaline ions.