Acta Chimica Sinica ›› 2013, Vol. 71 ›› Issue (05): 810-814.DOI: 10.6023/A13010107 Previous Articles     Next Articles



姜春杰a, 孙胜男a, 王旭阳a, 王祥生b, 郭洪臣b, 郭新闻b, 陈立东a   

  1. a 辽宁师范大学功能材料化学研究所 大连 116029;
    b 大连理工大学精细化工国家重点实验室 大连 116024
  • 投稿日期:2013-01-21 发布日期:2013-03-26
  • 通讯作者: 陈立东,; Tel.: 0411-82156915
  • 基金资助:

    项目受中国博士后科学基金面上项目(No. 20080441109)和国家自然科学基金(No. 21171082)资助.

Synthesis of Dimethyl Ether from Methanol over Heteropoly Acid/Nanocrystalline HZSM-5 Complex Solid Acidic Catalyst

Jiang Chunjiea, Sun Shengnana, Wang Xuyanga, Wang Xiangshengb, Guo Hongchenb, Guo Xinwenb, Chen Lidonga   

  1. a Institute of Chemistry for Functionalized Materials, Liaoning Normal University, Dalian 116029, China;
    b State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, China
  • Received:2013-01-21 Published:2013-03-26
  • Supported by:

    Project supported by China Postdoctoral Science Foundation (No. 20080441109) and the National Natural Science Foundation of China (No. 21171082).

Exploiting the catalysts with higher activity and stability for methanol dehydration at low temperature has become the central part of research dimethyl ether from synthesis gas or methanol. The crystal size of HZSM-5 zeolite is 50~100 nm. The nanocrystalline HZSM-5 zeolite is thought to be an ideal material for the encapsulation of heteropoly acid (HPA) molecules having a Keggin or Dawson structure since they have the intergranular secondary pores. A HPA/nanocrystalline HZSM-5 complex solid acidic catalyst was prepared by an impregnation method and characterized by FT-IR, UV-Raman, XRD and 31P MAS-NMR. The 12-phosphotungstic acid (HPW) loaded on nanocrystalline HZSM-5 zeolites was prepared by the following steps. The strip (ф 1 mm×2 mm) nanocrystalline HZSM-5 (Si/Al=4.2) catalyst was prepared by the procedure that reported in the literature. 1.00 g HPW was dissolved in 15 mL deionized water. 10.0 g of the strip nanocrystalline HZSM-5 zeolite were added into the solution and steeped the mixture for 12 h. The slurry mixture was calcined at 350 ℃ for 4 h. This catalyst is denoted HPW-HZSM-5. The FT-IR spectroscopy, UV-Raman spectroscopy and 31P MAS-NMR of HPW-HZSM-5 characterization results show that the Dawson type structure was well preserved after calcination of the catalysts. The reaction was carried out in a continuous flow fixed-bed reactor (diameter 10 mm). Reaction conditions are listed as following: temperature 200 ℃, WHSV=1.6, FRH (methanol flow rate)=0.08 mL/min; FRH (N2 flow rate)=8.0 mL/min; catalyst 2.05 g; system pressure 0.8 MPa. The composition of the products was analyzed by a GC-8820 gas chromatograph equipped with FID and a GDX-403 (2 m×4 mm). The reaction performance results, including methanol conversion and dimethyl ether selectivity were subsequently calculated. Under steady state conditions, the catalyst shows good stability, and the conversion of methanol maintains above 87.0 mol% (90.9 mol%) during 300 h, it also shows the selectivity (99.0 mol%) of dimethyl ether under the experimental conditions.

Key words: 12-phosphotungstic acid, nanocrystalline HZSM-5 zeolite, methanol dehydration, dimethyl ether