二氧化锆负载碱金属催化剂的制备及其催化葡萄糖转化性能

采用浸渍法和离子交换法制备了3种碱金属(Na、K、Cs)负载于二氧化锆(ZrO₂)的催化剂，考察了其在不同反应温度和反应时间下对葡萄糖脱水制备5-羟甲基糠醛(5-HMF)的催化效果。通过X射线衍射(XRD)、电感耦合等离子体质谱仪(ICP-MS)、N₂等温吸附-脱附、热重(TGA)和CO₂吸附量热等表征手段，研究3种催化剂的结构和性能，分析ZrO₂负载碱金属促进葡萄糖脱水转化为5-HMF的反应机理。结果表明：K/ZrO₂催化剂的晶粒最小、比表面积最大、热稳定性最好，其催化效率最高；在最佳反应温度200℃下，K/ZrO₂催化葡萄糖的转化率最高可达97%,5-HMF的收率可达15%,转化率和选择性随反应时间变化很小，催化剂稳定性较好。

Preparation of Zirconium Dioxide Supported Alkali Metal Catalyst and Its Catalytic Performance for Glucose Conversion

Three alkali metal (Na, K, Cs) catalysts supported on zirconium dioxide (ZrO₂) were prepared by impregnation method and ion exchange method, and their catalytic effects on the dehydration of glucose to 5-hydroxymethylfurfural (5-HMF) at different reaction temperatures and reaction time were investigated. By means of X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), N₂ isothermal adsorption-desorption analysis, thermal gravimetric analyzer (TGA) and CO₂ adsorption calorimetric, this paper studies the structure and performance of these three catalysts, and further analyzes the mechanism of ZrO₂ supported alkali metal for promoting the conversion of glucose into 5-HMF by dehydration. The results show that K/ZrO₂ catalyst has the smallest crystalline grain, largest specific surface area, and best thermal stability, so its catalytic efficiency is the highest. At the optimal reaction temperature of 200 ℃, the conversion rate of K/ZrO₂ catalyzed glucose can reach up to 97%, the yield of 5-HMF can reach 15%, and the conversion rate and selectivity change little over time, indicating that the catalyst has good stability.