介孔磷酸铌一锅法催化葡萄糖制备5-羟甲基糠醛

One-pot Catalytic Preparation of 5-Hydroxymethylfurural from Glucose on Mesoporous Niobium Phosphate

水热法制得介孔磷酸铌（m-NbP）固体酸催化剂,并用X-射线衍射（XRD）、氮气吸脱附、扫描电镜（SEM）、透射电镜（TEM）、氨气程序升温脱附（NH3-TPD）、吡啶吸附红外光谱（Py-FTIR）等手段对m-NbP进行了结构和酸性质表征。将m-NbP用于催化水-DMSO两相体系葡萄糖一锅法合成5-羟甲基糠醛（5-HMF）,考察了催化剂用量、水与DMSO体积比、反应温度、反应时间及催化剂循环利用次数对5-HMF收率的影响,并与其他三种催化剂（Amberlyst-15、Nb2O5及m-NbP-F127）比较催化性能。结果表明,m-NbP具有介孔结构和大量表面强酸性位,因而催化性能突出;当m（葡萄糖）∶m（m-NbP）=2∶1、V（水）∶V（DMSO）=1∶1、170℃反应1.5 h时,5-HMF的收率高达47.0%,且m-NbP经烧焦再生可重复利用5次而无明显失活。因此,m-NbP固体酸催化性能突出,能够高效催化葡萄糖一锅法制备5-HMF。

A kind of mesoporous niobium phosphate （m-NbP） solid acid catalyst was successfully synthesized via convenient hydrothermal method. The obtained catalyst was characterized by X-ray diffraction （ XRD）, nitrogen adsorption-desorption, scanning electron microscopy （ SEM ）, transmission electron microscopy （TEM）, temperature-programmed desorption of ammonia （NH3-TPD） and Fourier transform infrared spectra of pyridine adsorption （Py-FTIR）. Then, the one-pot conversion of glucose to 5-hydroxymethylfurural （5-HMF） in a biphasic water/DMSO medium was investigated on the m-NbP catalyst. The factors affecting the yield of 5-HMF such as catalyst dosage, volume ratio of water to DMSO, reaction temperature, reaction time, and catalyst recyclability were studied. Moreover, the catalytic performance of m-NbP was compared with other three catalysts （Amberlyst-15, NbzO5 and m-NbP- F127）. The results indicated that the m-NbP catalyst exhibited a promising catalytic performance for the preparation of 5-HMF due to its porous structure and adequate strong acid sites. The yield of 5-HMF could be as high as 47.0% at 170 ℃ within 1.5 h when the mass ratio of glucose to m-NbP was 2：1 and the volume ratio of water to DMSO was 1：1. Noticeably,the m-NbP catalyst could be recycled to reuse, after recycled five times, it showed no obvious deactivation after high-temperature calcinationregeneration. Therefore, the as-prepared m-NbP is an efficient catalyst for one-pot preparation of 5-HMF.