对比研究了二甲醚在氢型丝光沸石和吡啶修饰的氢型丝光沸石上的二甲醚羰基化反应.结果表明,吡啶预吸附大大提高了二甲醚羰基化反应的稳定性,并且在473K反应48h能够保持约30%的乙酸甲酯收率.原位红外光谱和NH3程序升温脱附研究发现,吡啶吸附在12元环内,而8元环内的酸性位基本不受干扰. 129Xe核磁共振研究表明,未经修饰的丝光沸石反应后孔道严重堵塞,而吡啶修饰的分子筛反应后孔道基本不变.因此,12元环内酸性位是积炭失活位,吡啶吸附抑制了12元环内积炭的生成,二甲醚羰基化反应能够在8元环内活性位上顺利进行.
The carbonylation of dimethyl ether to methyl acetate over H-mordenite (HMOR) and pyridine-modified HMOR was compared. The catalytic stability of HMOR was improved significantly by pyridine pre-adsorption, and a yield of methyl acetate ～30% was still ob-tained after 48 h on stream at 473 K. In situ infrared spectroscopy and ammonia temperature-programmed desorption revealed that pyridine preferentially occupied the acidic sites in 12-membered ring pores but not the acidic sites in 8-membered ring pores, 129Xe NMR studies suggested that the channels of HMOR were blocked by coke in the reaction but those in the pyridine-modified HMOR were not. The acidic sites in the 12-membered ring pores were responsible for the deactivation of HMOR, and the reaction can be directed to occur mainly on the acidic sties in the 8-membered ring pores by the selective adsorption of pyridine in the 12-membered ring pores.
参考文献
| [1] | Sunley G J;Watson D J .[J].Catalysis Today,2000,58:293. |
| [2] | Fujimoto K;Shikada T;Omata K;Tominnaga H.[J].Chemistry Letters,1984:2047. |
| [3] | Ellis B;Howard M J;Joyner R W;Reddy K N Padley M B Smith W J .[J].Studies in Surface Science and Catalysis,1996,101:771. |
| [4] | Wegman R W.[J].Journal of the Chemical Society,Chemical Communications,1994:947. |
| [5] | Volkova G G;Plyasova L M;Salanov A N;Kutova G N Yurieva T M Likholobov V A .[J].Catalysis Letters,2002,80:175. |
| [6] | Volkova G G;Plyasova L M;Shkuratova L N;Budneva A A Paukshtis E A Timofeeva M N Likholobov V A .[J].Studies in Surface Science and Catalysis,2004,147:403. |
| [7] | Cheung P;Bhan A;Sunley G J;Iglesia E .[J].Angewandte Chemie International Edition,2006,45:1617. |
| [8] | Cheung P;Bhan A;Sunley G J;Law D J Iglesia E .[J].Journal of Catalysis,2007,245:110. |
| [9] | Bhan A;Allian A D;Sunley G J;Law D J Iglesia E .[J].Journal of the American Chemical Society,2007,129:4919. |
| [10] | Blasco T;Boronat M;Concepcion P;Corma A,Law D,Vidal-Moya J A .[J].Angewandte Chemie International Edition,2007,46:3938. |
| [11] | Jiang Y;Hunger M;Wang W .[J].Journal of the American Chemical Society,2006,128:11679. |
| [12] | Boronat M;Martinez-Sanchez C;Law D;Corma A .[J].Journal of the American Chemical Society,2008,130:16316. |
| [13] | Beck C;Mallat T;Burgi T;Baiker A .[J].Journal of Catalysis,2001,204:428. |
| [14] | Muller C.A. .Amine-modified titania-silica hybrid gels as epoxidation catalysts[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,2000(2):253-261. |
| [15] | Corma A.;Martinez A.;Esteve P. .SOLVENT EFFECTS DURING THE OXIDATION OF OLEFINS AND ALCOHOLS WITH HYDROGEN PEROXIDE ON TI-BETA CATALYST - THE INFLUENCE OF THE HYDROPHILICITY-HYDROPHOBICITY OF THE ZEOLITE[J].Journal of Catalysis,1996(1):11-19. |
| [16] | Fang L Y;Liu S B;Wang I .[J].Journal of Catalysis,1999,185:33. |
| [17] | Sano T;Wakabayashi S;Oumi Y;Uozumi T .[J].Microporous and Mesoporous Materials,2001,46:67. |
| [18] | Makarova MA.;Vanliemt BJ.;Mesters CMAM.;Dewinter AW. Williams C.;Wilson AE. .QUANTIFICATION OF BRONSTED ACIDITY IN MORDENITES[J].Journal of Catalysis,1997(1):170-177. |
| [19] | Bagnasco G .[J].Journal of Catalysis,1996,159:249. |
| [20] | Viswanadham, N;Kumar, M .Effect of dealumination severity on the pore size distribution of mordenite[J].Microporous and Mesoporous Materials,2006(1/3):31-37. |
| [21] | Zholobenko V L;Makarova M A;Dwyer J .[J].Journal of Physical Chemistry,1993,97:5962. |
| [22] | Eder F;Stockenhuber M;Lercher J A .[J].Journal of Physical Chemistry B,1997,101:5414. |
| [23] | Maache M;Janin A;Lavalley J C;Benazzi E .[J].Zeolites,1995,15:507. |
| [24] | Auroux A;Datka J .[J].Applied Catalysis A:General,1997,165:473. |
| [25] | Buzzoni R;Bordiga S;Ricchiard G;Lamberti C,Zecchina A,Bellussi G .[J].Langmuir,1996,12:930. |
| [26] | Kresnawahjuesa O;Gorte R J;White D .[J].Journal of Molecular Catalysis A:Chemical,2004,208:175. |
| [27] | Springuel-Huet M A;Fraissard J P .[J].Zeolites,1992,12:841. |
| [28] | Pradhan A R;Wu J F;Jong S J;Chen W H Tsai T C Liu S B .[J].Applied Catalysis A:General,1997,159:187. |
| [29] | Yang J H;Clark L A;Ray G J;Kim Y J Du H Snurr R Q .[J].Journal of Physical Chemistry B,2001,105:4698. |
| [30] | Yuvaraj S;Chang T H;Yeh C T .[J].Journal of Catalysis,2004,221:466. |
| [31] | Palumbo L;Bonino F;Beato P;Bjorgen M Zecchina A Bordiga S .[J].Journal of Physical Chemistry C,2008,112:9710. |
| [32] | Guisnet M;Magnoux P .[J].Applied Catalysis A:General,2001,212:83. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%