铈改性Silicalite-1分子筛催化剂上甲醇制丙烯反应性能研究  

Catalytic performance of cerium modified Silicalite-1 molecular sieves in the conversion of methanol to propene

作　　者：黄慧文[1] 张敏秀[1] 陈晨[1] 李春义[1] 崔秋凯 

机构地区：[1]中国石油大学(华东)重质油国家重点实验室,山东青岛266580 [2]大港石化公司,中国石油有限公司,天津300280

出　　处：《燃料化学学报》2016年第12期1485-1493,共9页Journal of Fuel Chemistry and Technology

基　　金：国家重点基础研究发展规划(973计划,2012CB215006)资助~~

摘　　要：采用浸渍法制备了Ce改性的Silicalite-1分子筛催化剂,利用XRD、N2吸脱附、Py-FTIR和NH_3-TPD等手段对催化剂进行了表征;针对甲醇转化制丙烯(MTP)反应,在常压、450℃和质量空速为9.6 h-1的反应条件下,利用连续流动固定床微型反应评价装置,考察了CeO_2负载量对CeO_2/Silicalite-1催化性能的影响。结果表明,与HZSM-5分子筛(SiO_2/Al_2O_3(molar ratio)=200)相比,Silicalite-1分子筛具有更高的丙烯选择性和催化稳定性。Ce的引入可有效调节Silicalite-1分子筛的酸性质和孔结构;合适浓度的Ce改性处理(CeO_2负载量(质量分数)为5.0%)使得Silicalite-1的强酸量降低,其丙烯选择性(质量分数)和催化稳定性分别由原来的31.9%和51 h增加到38.2%和72 h。A series of cerium modified Silicalite- 1 molecular sieves were prepared by incipient wetness impregnation and used as the catalysts in the conversion of methanol to propene （ M T P ） . The cerium modified Silicalite-1 catalysts were characterized by X-ray diffraction （ XRD ）,N2 sorption,pyridine adsorption Fourier transform infrared spectroscopy （ P y - F T I R） and temperature-programmed desorption of N H 3 （ NH 3 - T P D ） ; their catalytic performance in MTP was evaluated in a continuous flow fixed-bed micro-reactor at atmospheric pressure and 450 益,with a methanol weight hourly space velocity （ WHSV ） of 9. 6 h-1. The results showed that Silicalite-1 exhibits superior catalytic performance in MTP in terms of catalytic stability and selectivity to propene, in comparison with the HZSM - 5 zeolite with a SiO2 /Al2O3 molar ratio of 200. The introduction of Ce can effectively adjust the acid properties and pore structure of Silicalite- 1 ; modification with an appropriate concentration of Ce can reduce the amount of strong acid sites and then enhance the catalytic performance of Silicalite-1 in MTP . Over the cerium modified Silicalite- 1 with a CeO2 content of 5. 0% ,the selectivity to propene is increased from 31.9% to 38. 2% and the catalytic lifetime is extended from 51 to 72 h , in comparison with those over the parent Silicalite- 1.

关 键 词：甲醇 丙烯 SILICALITE-1 铈 酸性 

分 类 号：TQ536.9[化学工程—煤化学工程]