二维层状H型丝光沸石的二甲醚羰基化性能

摘要

采用水热法合成了H型丝光沸石(H-MOR-S),考察了其二甲醚(DME)羰基化合成乙酸甲酯(MA)的活性,并与购买的商业H型丝光沸石(H-MOR-C)的羰基化活性进行比较.结果表明,水热法合成的样品H-MOR-S在180 ℃具有较高的DME羰基化活性,DME转化率可达到53.0%;但购买的样品H-MOR-C的DME转化率仅为20.5%.通过XRD和BET表征发现:样品H-MOR-S具有更大的比表面积,尤其是微孔比表面积和体积较大,其平均孔径为0.430 nm,接近八元环通道的大小,表明该样品中有更多八元环尺寸的通道,从而具有更多的DME吸附活性位,有助于提高催化剂的DME羰基化性能;通过SEM表征发现:样品H-MOR-S呈椭球状颗粒分布,每个颗粒由光滑二维平面成层状沿分子筛c轴方向整齐有序堆叠起来,提高了分子扩散速度,因而表现出较高的DME羰基化活性.

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	牛君阳
	刘亚华
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	李新刚

关键词：水热法； H型丝光沸石；二维层状；二甲醚；羰基化

Abstract：

The H-Mordenite (H-MOR) was prepared by a hydrothermal method. The catalytic activity of H-MOR upon carbonylation of dimethyl ether (DME) to methyl acetate (MA) was investigated and it was compared with the commercial H-Mordenite. Our results showed that the synthesized sample (H-MOR-S) presented the higher catalytic carbonylation activity: the DME conversion reached 53.0% after 4.5 h on stream at 180 ℃, while the DME conversion of the commercial sample (H-MOR-C) was only 20.5% under the same reaction conditions. The XRD and BET results demonstrate that the sample H-MOR-S has the larger BET surface areas, and especially larger micropore surface areas and volumes. The average pore size of the H-MOR-S sample is close to the size of the eight-membered ring (8-MR) channels in zeolites. It indicates the increased amount of the 8-MR channels in the H-MOR-S sample further improves the DME carbonylation activity. SEM images clearly show that the H-MOR-S sample is in the form of the ellipsoidal particles assembled of smoothly and orderly two-dimensional sheets. This morphology accelerates the diffusion rate of reactants, as well as products, in the c-axis direction, which thus enhances the DME carbonylation activities.

Keywords： hydrothermal method； H-Mordenite； two-dimensional layered； dimethyl ether； carbonylation

Received 2014-03-17;

Fund:

国家自然科学基金(21476159,U1162103);教育部新世纪优秀人才支持计划(NCET-10-0615);教育部留学归国人员科研启动基金(2011-1568);天津大学绿色合成与转化教育部重点实验室开放基金.

Corresponding Authors: 李新刚,E-mail: xingang_li@tju.edu.cn. Email: xingang_li@tju.edu.cn

About author: 牛君阳(1987-),女,硕士研究生,主要从事能源催化方面的研究工作.

引用本文:

牛君阳, 刘亚华, 董红文, 李新刚.二维层状H型丝光沸石的二甲醚羰基化性能[J]. 化学工业与工程, 2015,32(6): 7-12

Niu Junyang, Liu Yahua, Dong Hongwen, Li Xingang.Carbonylation of Dimethyl Ether over the Two-Dimensional Layered H-Mordenite[J]. Chemcial Industry and Engineering, 2015,32(6): 7-12

[1] Spivey J J, Egbebi A. Heterogeneous catalytic synthesis of ethanol from biomass-derived syngas[J]. Chemical Society Reviews, 2007, 36(9): 1 514-1 528
[2] Subramani V, Gangwal S K. A review of recent literature to search for an efficient catalytic process for conversion of syngas to ethanol[J]. Energy & Fuels, 2008, 22(2): 814-839
[3] Mei D H, Rousseau R, Kathmann S M, et al. Ethanol synthesis from syngas over Rh-based/SiO₂ catalyst: A combined experimental and theoretical modeling study[J]. Journal of Catalysis, 2010, 271(2): 325-342
[4] 唐宏青.合成乙醇新技术展望[J]. 中氮肥, 2012, (2): 1-6, 64 Tang Hongqing. Outlook for new ethanol synthesis technology[J]. M-Sized Nitrogenous Fertilizer Progress, 2012, (2): 1-6, 64(in Chinese)
[5] Chum H L, Overend R P. Biomass and renewable fuels[J]. Fuel Processing Technology, 2001, 71(1): 187-195
[6] 刘晓娟, 吴晓斌, 郑文耀, 等. 玉米芯HNO₃/HCl预处理及同步糖化发酵制乙醇[J]. 化学工业与工程, 2013, 30(5): 16-20 Liu Xiaojuan, Wu Xiaobin, Zheng Wenyao, et al. Pretreatment of corn cob with HNO₃/HCl and ethanol production by simultaneous saccrification and fermentation [J]. Chemical Industry and Engineering, 2013, 30(5): 16-20(in Chinese)
[7] Pan X, Fan Z, Chen W, et al. Enhanced ethanol production inside carbon-nanotube reactors containing catalytic particles[J]. Nature Materials, 2007, 6(7): 507-511
[8] Haider M A, Gogate M R, Davis R J. Fe-Promotion of supported Rh catalysts for direct conversion of syngas to ethanol[J]. Journal of Catalysis, 2009, 261(1): 9-16
[9] Li X, San X, Zhang Y, et al. Direct synthesis of ethanol from dimethyl ether and syngas over combined H-Mordenite and Cu/ZnO catalysts[J]. Chem Sus Chem, 2010, 3(10): 1 192-1 199
[10] Yang G, San X, Jiang N, et al. A new method of ethanol synthesis from dimethyl ether and syngas in a sequential dual bed reactor with the modified zeolite and Cu/ZnO catalysts[J]. Catalysis Today, 2011, 164(1): 425-428
[11] 伞晓广, 任庆生. 二甲醚合成乙醇的新方法[J]. 甲醇生产与应用技术, 2010, (1): 23-25 San Xiaoguang, Ren Qingsheng. A new method of ethanol synthesis from dimethyl ether[J]. Production and Application Technology of the Methanol, 2010, (1): 23-25(in Chinese)
[12] Claus P, Lucas M, Lücke B, et al. Selective hydrogenolysis of methyl and ethyl acetate in the gas phase on copper and supported group VIII metal catalysts[J]. Applied Catalysis A: General, 1991, 79(1): 1-18
[13] Cheung P, Bhan A, Sunley G J, et al. Site requirements and elementary steps in dimethyl ether carbonylation catalyzed by acidic zeolites[J]. Journal of Catalysis, 2007, 245(1): 110-123
[14] Bhan A, Allian A D, Sunley G J, et al. Specificity of sites within eight-membered ring zeolite channels for carbonylation of methyls to acetyls[J]. Journal of the American Chemical Society, 2007, 129(16): 4 919-4 924
[15] Cheung P, Bhan A, Sunley G J, et al. Selective carbonylation of dimethyl ether to methyl acetate catalyzed by acidic zeolites[J]. Angewandte Chemie International Edition, 2006, 45(10): 1 617-1 620
[16] Bhan A, Iglesia E. A link between reactivity and local structure in acid catalysis on zeolites[J]. Accounts of Chemical Research, 2008, 41(4): 559-567
[17] Liu J, Xue H, Huang X, et al. Stability enhancement of H-mordenite in dimethyl ether carbonylation to methyl acetate by pre-adsorption of pyridine[J]. Chinese Journal of Catalysis, 2010, 31(7): 729-738
[18] Boronat M, Martinez-Snchez C, Law D, et al. Enzyme-Like specificity in zeolites: A unique site position in mordenite for selective carbonylation of methanol and dimethyl ether with CO[J]. Journal of the American Chemical Society, 2008, 130(48): 16 316-16 323