物理化学学报 >> 2012, Vol. 28 >> Issue (10): 2349-2354.doi: 10.3866/PKU.WHXB201207312

催化和表面科学 上一篇    下一篇

介孔磷酸铌一锅法高效催化木糖制备糠醛

李相呈, 张宇, 夏银江, 胡必成, 钟霖, 王艳芹, 卢冠忠   

  1. 华东理工大学工业催化研究所, 上海 200237
  • 收稿日期:2012-06-11 修回日期:2012-07-30 发布日期:2012-09-26
  • 通讯作者: 张宇, 王艳芹 E-mail:zhangyu8701@gmail.com; wangyanqin@ecust.edu.cn
  • 基金资助:

    国家自然科学基金(20973058)和中央高校交叉学科与重大项目培育基金资助项目

One-Pot Catalytic Conversion of Xylose to Furfural on Mesoporous Niobium Phosphate

LI Xiang-Cheng, ZHANG Yu, XIA Yin-Jiang, HU Bi-Cheng, ZHONG-Lin, WANG Yan-Qin, LU Guan-Zhong   

  1. Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2012-06-11 Revised:2012-07-30 Published:2012-09-26
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20973058) and Fundamental Research Funds for the Central Universities, China.

摘要:

木糖转化到糠醛一般包括两步: 首先在酶、碱或路易斯(L)酸的催化作用下异构化木糖到木酮糖, 接下来木酮糖在酸的作用下脱水得到糠醛. 针对木糖水相脱水一步制备糠醛, 利用十六烷基三甲基溴化铵(CTAB)为模板剂, 借助软模板合作策略制备了一种抗水的新型固体酸催化剂, 介孔磷酸铌, 并利用X射线衍射(XRD)、N2吸脱附、透射电镜(TEM)、氨气程序升温脱附(NH3-TPD)和吡啶吸附傅里叶变换红外(Py-FTIR)光谱对材料的结构和酸性质进行了表征. 研究发现介孔磷酸铌不仅具有很高的比表面积(>200 m2·g-1), 比较窄的孔径分布(3.5nm), 同时还具有很强的L酸性和布朗斯特(B)酸性. 通过L酸催化的木糖异构化为木酮糖/来苏糖和B酸催化的木酮糖/来苏糖进一步脱水得到糠醛, 实现了一步由木糖到糠醛的高效转化. 为了优化反应条件, 考察了水溶液中反应温度、投料质量比及反应时间对木糖转化率和糠醛收率的影响, 在最佳的反应条件下, 木糖的转化率为96.5%, 糠醛的收率达49.8%. 进一步地, 为了提高收率且易于分离, 利用4-甲基-2-戊酮(MIBK)/NaCl水溶液(体积比为7:3)作为反应混合溶剂, 使糠醛收率提高到68.4%.

关键词: 介孔磷酸铌, 布朗斯特酸, 路易斯酸, 木糖, 糠醛, 水相, 双相

Abstract:

The conversion of xylose to furfural normally involves two steps: the isomerization of xylose to xylulose catalyzed by an enzyme, a base or a Lewis acid, followed by the acid-catalyzed dehydration of xylulose to furfural. To allow a more efficient single-step conversion, a new water-tolerant solid acid catalyst, mesoporous niobium phosphate was synthesized. This synthesis was performed using a soft template approach, with cetyltriethylammonium bromide (CTAB) as the template. The structure and properties of the catalyst thus synthesized were investigated by X-ray diffraction (XRD), N2 sorption, transmission electron microscopy (TEM), temperature-programmed desorption of NH3 (NH3-TPD), and pyridine sorption FTIR (Py-FTIR). These studies determined that the niobium phosphate not only had a large surface area (>200 m2·g-1) and narrow pore size distribution (3.5 nm), but also had relatively strong Lewis and Brønsted acidity. This catalyst was found to be capable of producing furfural via a simple one-pot process, including the isomerization of xylose to xylulose and subsequent dehydration. The influence of several variables including temperature, mass ratio of xylose/catalyst, and reaction time on the extent of xylose conversion and furfural yield were studied. Under optimal conditions, the yield of furfural in aqueous solution reached 49.8% with 96.5% xylose conversion. It was further determined that both the yield and the separation of furfural could be improved by employing a methyl isobutyl ketone (MIBK)/water (volume ratio 7:3) biphase containing NaCl in the aqueous phase, resulting in a 68.4% yield.

Key words: Mesoporous niobium phosphate, Brö, nsted acid, Lewis acid, Xylose, Furfural, Aqueous phase, Biphase

MSC2000: 

  • O643