氧化铌的制备及以其催化葡萄糖制备5-羟甲基糠醛

Preparation of Niobium Oxide and Its Catalytic Performances During Conversion of Glucose to 5-Hydroxymethylfurfural

为了改进现有氧化铌制备工艺的缺点,以糖尿素熔融体系一步法制备了氧化铌催化剂,并通过X-射线衍射、氮气吸附脱附、氨气程序升温脱附、吡啶吸附红外光谱、扫描电镜等表征对催化剂的结构和酸性进行了分析。将该催化剂应用于水和仲丁醇双相体系中催化葡萄糖转化为5-羟甲基糠醛(5-HMF),考察了反应时间、反应温度、催化剂用量、底物含量及催化剂重复使用次数对催化活性的影响。结果表明:当催化剂用量为0.06 g,底物质量分数为5%,160℃反应4 h时5-HMF的收率可达34.96%,选择性为35.32%,葡萄糖转化率为99%,催化剂经重复使用5次催化活性无明显下降。

To improve the existing preparation process of niobium oxide,the niobium oxide catalyst was prepared by a one-step method in a sugar-urea-melt system.The structure X-ray diffraction,nitrogen adsorption desorption,and scanning electron microscopy.And acidity properties of the catalyst were analyzed by ammonia temperature programmed desorption,pyridine adsorption infrared spectroscopy.The catalyst is applied for the conversion of glucose to 5-hydroxymethylfurfural(5-HMF)in the biphasic system of water and sec-butanol.The effects of reaction time,reaction temperature,catalyst dosage,substrate content and catalyst reuse times on the catalytic activity were investigated.The results showed that the yield of 5-HMF is 34.96%,the selectivity is 35.32%,and the glucose conversion is 99%when the catalyst dosage is 0.06 g,the mass fraction of substrate is 5%,the reaction time is 4 h and the reaction temperature is 160℃.The catalyst could be reused at least five times without any obvious deactivation.