介孔磷酸铌一锅法催化葡萄糖制备5-羟甲基糠醛

One-pot Production of 5-Hydroxymethylfurural from Glucose over Mesoporous Niobium Phosphate Catalyst

摘要:

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)=5:5、170 ℃反应1.5 h，5-HMF的收率高达47.0%，且m-NbP经烧焦再生可重复利用6次以上而无明显失活。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。

Abstract:

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 Infrared spectra of pyridine adsorption (Py-FTIR) etc in order to elucidate its structural and acidic properties. The one-pot conversion of glucose to 5-hydroxymethylfurural (5-HMF) in a biphasic water/DMSO medium was also investigated over the m-NbP catalyst. The catalyst dosage, volume ratio of water to DMSO, reaction temperature, reaction time, catalyst recyclability, comparison of catalytic performance with other three catalysts (Amberlyst-15, Nb2O5 and m-NbP-F127) etc were studied in detail. The results indicated that the catalyst exhibited the promising catalytic performance for 5-HMF production probably assigned to the porous structure and the adequate strong acid sites. The 5-HMF yield could be obtained as high as 47.0% at 170 ℃ within 1.5 h when the mass ratio of glucose to m-NbP and volume ratio of water to DMSO was 2:1 and 5:5 respectively. Noticeably, the m-NbP catalyst could be recycled up to 6 times without any obvious deactivation after high-temperature calcination-regeneration. This work was the continue efforts for the development of efficient solid catalyst for excellent conversion of one-pot glucose to 5-HMF.