In this study, a mesoporous Nb-W oxide solid acid catalyst was synthesized and characterized in detail by TEM, N₂ physisorption, and Py-FTIR. Effects of the calcination temperature on the pore structure and acid properties were investigated. The results showed that increasing calcination temperature from 400 °C to 600 °C remarkably affected the characteristics of mesoporous Nb-W oxides, with a decrease in specific surface area, pore volume, and acid amount, but an increase in pore size from 5.1 nm to 10.4 nm. Furthermore, a notable decrease was found in both the fructose conversion and HMF yield in the dehydration of fructose to HMF over Nb-W oxides when increasing the calcination temperature, and the catalyst could keep high catalytic activity and selectivity after recycling 4 times. Solvents also played a key role in the fructose dehydration to HMF over the Nb-W oxides, and DMSO was the optimized solvent. ¹H NMR and ¹³C NMR experiments revealed that the key intermediate, 4-hydroxy-5-hydroxymethyl-4,5-dihydrofuran-2-carbaldehyde, could generate in DMSO but not in other solvents including NMP, DMF, DMAC, and EG.

_{在这项研究中，合成了一种介孔 Nb-W 氧化物固体酸催化剂，并通过 TEM、N 2}物理吸附和 Py-FTIR对其进行了详细表征。研究了煅烧温度对孔结构和酸性质的影响。结果表明，将煅烧温度从 400 °C 提高到 600 °C 显着影响介孔 Nb-W 氧化物的特性，比表面积、孔体积和酸量降低，但孔径从 5.1 nm 增加到 10.4 纳米。此外，当焙烧温度升高时，Nb-W氧化物上果糖脱水制HMF的果糖转化率和HMF收率均显着降低，催化剂仍能保持较高的催化活性和选择性回收4次后。溶剂在 Nb-W 氧化物上的果糖脱水为 HMF 中也起着关键作用，DMSO 是优化的溶剂。¹H NMR 和¹³C NMR 实验表明，关键中间体 4-hydroxy-5-hydroxymethyl-4,5-dihydrofuran-2-carbaldehyde 可以在 DMSO 中生成，但在 NMP、DMF、DMAC 和 EG 等其他溶剂中不能生成.