摘要
碳酸二乙酯(DEC)是环境友好的绿色化学品,是重要的有机合成中间体,特别是近年来发现DEC可以作为油品的含氧添加剂,取代MTBE的使用,应用前景广阔。本文对乙醇氧化羰基合成碳酸二乙酯(DEC)负载型铜钯系催化剂体系进行了研究。
本工作分别以HMS和Cu-HMS为载体,通过浸渍活性组分的方法制备了新型的催化剂CuCl_2-PdCl_2/HMS与PdCl_2/Cu-HMS。首先研究了CuCl_2-PdCl_2/HMS催化剂乙醇氧化羰基合成碳酸二乙酯(DEC)反应性能的影响,并考察了助剂对催化剂的影响。助剂的加入在不同程度上提高了CuCl_2-PdCl_2/HMS的催化活性,其中四乙基溴化胺(TEAB)的效果最为理想,产物DEC的时空收率达到210.9g /(L·h),转化率达到13.6%。XRD、XPS、IR与ESR等分析表明,助剂TEAB对载体的有序度起到一定的改善作用,进而提高了催化剂的催化活性。
另外,通过焙烧脱除模板剂的方法合成了含铜的中孔杂原子分子筛Cu-HMS,并对催化剂的结构及活性进行了探讨。采用XRD、XPS、ICP-AES、IR等表征手段,表明铜离子以高度分散的状态进入HMS骨架,并保持了良好的介孔结构的有序性,同时PdCl_2的负载一定程度上提高了Cu-HMS的介孔规整度。通过催化剂活性的考察发现,PdCl_2/Cu-HMS表现出较佳的选择性,助剂的加入在不同程度上提高了PdCl_2/Cu-HMS催化剂的活性,其中四乙基溴化胺(TEAB)的效果最为理想,产物DEC的时空收率达到187.93g /(L·h),其最佳修饰量为TEAB/Pd=12/1。不同Si/Cu比合成的Cu-HMS催化剂对于合成DEC催化活性具有一定影响,适宜的Si/Cu比为50/1时,可以有效提高催化剂的活性中心,同时保持介孔有序度性,从而提高催化活性。最后通过对PdCl_2/Cu-HMS催化剂体系反应机理的探讨,解释了表面的Pd与骨架中Cu之间的协同作用有利于该反应体系活性中心的形成。
Diethyl carbonate (DEC) is a versatile compound that represents an attractive eco-friendly alternative to both ethyl halides and phosgene for ethylation and carbonylation processes, respectively. In recent years, diethyl carbonate is found to substitute for methyl tert-butyl ether (MTBE), which is used as an oxygen-containing fuel additive. In this paper, supported PdCl_2-CuCl_2 catalysts for the vapor phase synthesis of DEC by the oxidative carbonylation of ethanol in the gas phase were studied.
Diethyl carbonate (DEC) has been produced by the oxidative carbonylation of ethanol in the gas phase over a heterogeneous PdCl_2-CuCl_2 catalyst supported on mesoporous HMS silica. The effects of the various quaternary ammonium salt (QAS) promoters and the promoter loading level were investigated. The catalytic performance of the PdCl_2-CuCl_2/HMS catalyst was greatly improved by the addition of promoter tetraethyl ammonium bromide (TEAB). Under the PdCl_2- CuCl_2-TEAB/HMS catalyst system, space time yield (STY) of DEC is 210.9 g /(L·h) , and conversion of EtOH is 13.6%. The functions of promoters were investigated on the basis of catalyst characterization and activity by means of X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), low-temperature electron spin resonance (ESR) spectroscopy, and infrared resonance (IR) spectroscopy. It can be concluded that the essential role of TEAB promoter is to improve the order degree of mesoporous structure, which is interrelated with the concentration of surface Si species.
PdCl_2/Cu-HMS has been investigated, which demonstrated excellent selectivity to DEC by oxidative carbonylation of ethanol in the gas-phase reaction. The effects of various quaternary ammonium salt (QAS) promoters and promoter loading amounts were investigated. The catalytic performances of the PdCl_2/Cu-HMS catalyst were significantly improved by the addition of a promoter tetraethyl ammonium bromide (TEAB). From XRD, XPS, ICP and IR characterization and analysis, it can be concluded that copper species incorporated into HMS frame and was highly dispersed in the frame of silica. An optimized Si/Cu ratio exists for catalytic activity, which is about 50/1. The catalytic performances of PdCl_2/Cu-HMS with the different Si/Cu ratio of the Cu-HMS support are related with both Cu content in the Cu-HMS and the order degree of mesoporous structure for Cu-HMS. The catalytic reaction mechanism was illuminated by the interaction between Pd~(2+) loaded on the surface and Cu~(2+) in Cu-HMS frame.
引文
[1] 许志宏,21 世纪绿色过程工程的发展,北京:中国石化出版社,2002
[2] G. Nagasubramanian, D. Doughty, Improving the interfacial resistance in lithium cells with additives, Journal of Power Sources, 2001,96(1): 29~32
[3] S.K. Jeong, M. Inaba, Y. Iriyama, et al, AFM study of surface film formation on a composite graphite electrode in lithium-ion batteries, Journal of Power Sources, 2003, 119-127: 555~560
[4] G. Moumouzias, G. Ritzoulis, D. Siapkas, et al, Comparative study of LiBF4, LiAsF6, LiPF6, and LiClO4 as electrolytes in propylene carbonate-diethyl carbonate solutions for Li/LiMn2O4 cells, Journal of Power Sources, 2003, 122: 57~66
[5] M. Herstedt, M. Stjerndahl, T. Gustafsson, et al, Anion receptor for enhanced thermal stability of the graphite anode interface in a Li-ion battery, Electrochemisty Communications, 2003, 5: 467~472
[6] J.S. Gnanaraj, E. Zinigrad, L. Asraf, et al, On the use of LiPF3(CF2CF3)3 (LiFAP) solutions for Li-ion batteries, Electrochemisty Communications, 2003, 5: 946~951
[7] M.A. Pacheco, C.L. Marshall, Review of dimethyl carbonate (DMC) Manufacture and its characteristics as a fuel additive, Energy & Fuels, 1997, 11: 2~29
[8] I.E. Muskat, F. Strain, Preparation of Carbonic Acid Esters, US Patent, 2379250, 1941-05-28
[9] 章思规,实用精细化学品手册 有机卷(上),北京: 化学工业出版社, 1996: 945~946
[10] 方云进,罗虎平,肖文德,制备碳酸二乙酯的方法,中国专利,01105860.9, 2001-04-03
[11] P.T. Anastas, J.C. Warner, Green Chemistry: Theory and Practice, London: Oxford University Press, 1998: 11~16
[12] L.K. Frevel, J.A. Gilpin, Carbonate synthesis from alkylene carbonates, US Patent, 3642858, 1969-02-12
[13] U. Yoshiaki, K. Masaru, O. Yoshiyuki, et al, Process for preparing diaklyl carbonates, US Patent, 5430170, 1993-11-23
[14] R. Ugo, M. Ugo, Process for the preparation of dialkylcarbonates, US Patent, 4062884, 1976-04-08
[15] H.J. Buysch, A. Klausener, R. Langer, et al, Process for the continuouspreparation of diakyl carbonates, US Patent, 5231212, 1992-08-26
[16] H. Krimm, H.J. Buysch, H. Rudolph, Process for the preparation of dialkyl carbonates, US Patent, 4307032, 1980-05-13
[17] H.J. Buysch, H. Krimm, H. Rudolph, Process for the preparation of dialkyl carbonates, US Patent, 4181676, 1978-08-31
[18] M. Doya, K. Kimizuka, Y. Kanbara, Process for the production of dialkyl carbonate, US Patent, 5489702, 1994-08-05
[19] 刘淑芝,崔宝臣,荆国林,非光气法合成碳酸二甲酯催化剂研究进展,化工进展,2002, 21(4): 250~253
[20] D.M. Fenton, Preparation of alkyl carbonates, US Patent, 3227740, 1963-02-25
[21] D.M. Fenton, Preparation of organic carbonates bearing disparate radicals, US Patent, 3227741, 1963-06-28
[22] 殷元骐,羰基合成化学,北京: 化学工业出版社,1995: 241~246
[23] B.C. Dunn, C. Guenneau, S.A. Hilton, et al, Production of diethyl carbonate from ethanol and carbon monoxide over a heterogeneous catalyst, Energy & Fuels, 2002, 16(1): 177~181
[24] R. Ugo, T. Renato, C. Gioacchino, et al, Method for the preparation of esters of carbonic acid, US Patent, 4218391, 1979-05-05
[25] 赵天生,韩怡卓,孙予罕,碳酸二甲酯合成方法的研究进展,石油化工,1998,27(6): 457~462
[26] M. Tanaka, T. Kimura, T. Shimoda, Method for manufacturing dialkyl carbonate, US Patent, 6258923, 2000-05-31
[27] T. Kimura, T. Shimoda, M. Tanaka, A method for manufacturing dialkyl carbonate, World, 0200596, 2001-06-21
[28] W.L. Mo, G.X. Li, Y.Q. Zhu, et al, A Novel Catalyst CuCl/ 1,10-Phenanthroline/ N-Methylimidazole for the Oxidative Carbonylation of Ethanol to Diethyl Carbonate, Chinese Journal of Catalysis, 2003, 24: 3~4
[29] 李光兴,朱永强,莫婉铃等,乙醇在 CuCl/Schiff 碱上催化氧化羰基合成碳酸二乙酯,应用化学,2003, 20: 163~166
[30] X.Z. Jiang, Y.H. Su, S.H. Chien, Novel synthesis of diethyl carbonate over palladium/MCM-41 catalysts, Catalysis Letters, 2000, 69: 153~156
[31] S. Umemura, K. Matsui, Y. Ikeda, et al, Process for preparing diesters of dicarboxylic acids, US Patent, 4260810, 1979-06-27
[32] K. Nishihira, K. Mizutare, S. Tanaka, Process for preparing a diester of carboxylic acid, US Patent, 5162563, 1990-10-17
[33] T. Matsuzaki, T. Shimamura, S. Fujitsu, et al, Method of producing carbonic acid diester, US Patent, 5292916, 1991-09-30
[34] N. Manada, M. Murakami, K. Abe, et al, Method of producing carbonic acid diester, US Patent, 5403949, 1993-06-29
[35] H. Landscheidt, A. Klausener, E. Wolters, Process for the preparation of dialkyl carbonates, US Patent, 5231213, 1992-06-08
[36] 苏跃华,姜玄真,常压气相羰基化合成碳酸二乙酯,现代化工,2002, 22(2): 33~36
[37] Y. Yasushi, M. Tokuo, T. Shuji, et al, Catalysis and characterization of Pd/NaY for dimethyl carbonate synthesis from methyl nitrite and CO, J Chem Soc, Faraday Tran, 1997, 93 (20): 3721~3727
[38] Y.J. Wang, X.Q. Zhao, B.G. Yuan, et al, Synthesis of dimethyl carbonate by gas-phase oxidative carbonylation of methanol on the supported solid catalyst I. Catalyst preparation and catalytic properties, Applied Catalysis A: General, 1998, 171: 255~260
[39] Ryu, J. Yong, Process for making dialkyl carbonates, US Patent, 5902894, 1999-05-11
[40] S.R. Yanni, M.R. Charles, S.E. Nausicaa, et al, Process for manufacturing dialkyl carbonate from urea and alcohol, US Patent, 5565603, 1996-10-15
[41] K. Tomishige, K. Ikeda, F. Kaori, et al, Catalytic Properties and Structure of Zirconia Catalysts for Direct Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide, Journal of Catalysis, 2000, 192: 355~362
[42] K. Tomishige, K. Kunimori, Catalytic and direct synthesis of dimethyl carbonate starting from carbon dioxide using CeO2-ZrO2 solid solution heterogeneous catalyst: Effect of H2O removal from the reaction system, Applied Catalysis A: General, 2002, 237 (1-2): 103~109
[43] 王书明,江琦,由二氧化碳出发合成有机碳酸酯,现代化工, 2002, 22(3): 18~22
[44] 王延吉,赵新强, 绿色催化过程与工艺,北京: 化学工业出版社, 2002: 95~97
[45] P. Foley, Production of carbonate diesters from oxalate diesters, US Patent, 4544507, 1984-02-06
[46] 原田胜正,衫濑良二,西尾正幸,碳酸二烷基酯的制备方法,中国专利, 98125031.9, 1998-11-7
[47] T. Cho, T. Tamura, T. Cho, et al, Process for preparing dialkyl carbonates, US Patent, 5534649, 1994-12-29
[48] M.A.P.J. Hacking, F.V. Rantwijk, R.A. Sheldon, Lipase catalyzed reactions of aliphatic and arylaliphatic carbonic acid esters, Journal of Molecular Catalysis B: Enzymatic, 2000, 9:201~208
[49] N.S. Roh, B.C. Dunn, E.M. Eyring, et al, Continuous production of diethyl carbonate over a supported CuCl2/PdCl2/KOH catalyst, Fuel Chemistry DivisionPreprints, 2002, 47(1): 142~143
[50] N.S. Roh, B.C. Dunn, E.M. Eyring, et al, Procuction of diethyl carbonate from ethanol and carbon monoxide over a heterogeneous catalytic flow reactor, Fuel Processing Technology, 2003, 83: 27~38
[51] A. Punnoose, M.S. Seehra, B.C. Dunn, et al, Characterization of CuCl2/PdCl2/Acitivated carbon catalysts for the synthesis of diethyl carbonate, Energy & Fuels, 2002, 16: 182~188
[52] Z. Li, K. C. Xie, R. C. T. Slade, Studies of the interaction between CuCl and HY zeolite for preparing heterogeneous Cu (Ⅰ) catalyst, Applied Catalysis A: General, 2001, 209: 107~115
[53] 李光兴,王克洪,向兴源,杨晓利,液相氧化羰化合成碳酸二甲酯中试研究,华中理工大学学报,1999,27:37~39
[54] 刘定华,赵贤广,王海善等,CuXnLm 体系催化合成碳酸二甲酯,化学工业与工程技术,1998,19(2):6~7
[55] Z. Li, K. C. Xie, R. C. T. Slade, High selective catalyst for oxidative carbonylation of methanol to dimethyl carbonate, Applied Catalysis A: General, 2001, 205: 85~92
[56] C.S. Chin, D. Shin, G. Won, et al, The effects of catalyst composition on the catalytic production of dimethyl carbonate, Journal of Molecular Catalysis A: Chemical, 2000, 160:315~321
[57] J. C. Hu, Y. Cao, P.Yang, et al, A novel homogeneous catalyst made of poly (N-vinyl-2-pyrrolidone)CuCl2 complex for the oxidative carbonylation of methanol to dimethyl carbonate, Journal of Molecular Catalysis A: Chemical, 2002, 185:1~9
[58] Y. Sato, M. Kagotani, Y. Souma, Poly (pyridine-2,5-diyl)-CuCl2 catalyst for synthesis of dimethyl carbonate by oxidative carbonylation: catalytic activity and corrosion influence, Catalysis Letters, 2000, 65: 123~126
[59] Y. Sato, M. Kagotani, Y. Souma, Novel effective poly (2,2’-pyridine-5,5’-diyl)-CuCl2 catalyst for synthesis of dimethyl carbonate (DMC) by oxidative carbonylation of methanol, Applied Catalysis A: General, 1999, 185: 219~226
[60] Y. Sato, M. Kagotani, Y. Souma, A new type of support bipyridine containing aromatic polyamide to CuCl2 catalyst for synthesis of dimethyl carbonate (DMC) by oxidative carbonylation of methanol, Journal of Molecular Catalysis A: Chemical, 2000, 151:79~85
[61] P. Yang, Y. Cao, J. C. Hu, et al, Mesoporous bimetallic PaCl2-CuCl2 catalysts for dimethyl carbonate synthesis by vapor phase oxidative carbonylation of methanol, Applied Catalysis A: General, 2003, 241: 363~373
[62] C. T. Kresge, M.E. Leonowicz, W. J. Roth, et al, Ordered mesoporous molecular-sieves synthesized by a liquid-crystal template mechanism, Nature,1992, 359:710~712
[63] J. S. Beck, J. C. Vartuli, W. J. Roth, et al, A new family of mesoporous molecular-sieves prepared with liquid-crystal templates, Journal of the American chemical society, 1992, 114:10834~10843
[64] A. Sayari, Y. Yang, M. Kruk, et al, Expanding the pore size of MCM-41 silicas: use of amines as expanders in direct synthesis and postsynthesis procedures, Journal of physical chemistry B, 1999, 103:3651~3658
[65] P. T. Tanev, T. J. Pinnavaia, A neutral templating route to mesoporous molecular sieves, Science, 1995, 267:865~867
[66] S. Inagaki, Y. Fukushima, K. Kuroda, Synthesis of highly ordered mesoporous materials from a layered polysilicate, Journal of chemical society, chemical communication, 1993, 680~682
[67] J. Y. Ying, C. P. Mehnert, M. S. Wong, Synthesis and applications of supramolecular-templated mesoporous materials, Angewandte chemie - international edition, 1999, 38(1-2): 57~77
[68] S. Gontier, A. Tuel, Novel zirconium containing mesoporous silicas for oxidation reactions in the liquid phase, Applied Catalysis A: General, 1996, 143(1): 125~135
[69] K. M. Reddy, C. Song, Synthesis of mesoporous molecular sieves: Influence of aluminum source on Al incorporation in MCM-41, Catalysis Letters, 1996, 36 (1-2):103~109
[70] W. Zhang, J.Wang, P. T. Tanev, T. J. Pinnavaia, Catalytic hydroxylation of benzene over transition-metal substituted hexagonal mesoporous silicas, Chemical Communications, 1996, (8):979~980
[71] Q. S. Huo, D. I. Margolese, U. Ciesla, et al, Generalized synthesis of periodic surfactant inorganic composite materials, Nature, 1994, 368:317~321
[72] 徐如人,庞文琴,于吉红等,分子筛与多孔材料化学,北京: 科学出版社, 2002: 544~545
[73] R.Szostak, Molecular Sieves, 2nd ed. London: Blackie Academic & Professional 1998, 234, 240.
[74] A. Tuel, Modification of mesoporous silicas by incorporation of heteroelements in the framework, Microporous and Mesoporous Materials, 1999, 27 (2-3): 151~169