制备了一系列不同La2O3含量(100Fe/2.8Si/nLa,n=0,0.5,1,2,4,原子比)的沉淀铁费-托合成催化剂,通过原位X射线衍射、一氧化碳程序升温还原和N2吸附-脱附等手段对催化剂进行了表征.催化剂费-托反应评价在固定床反应器中进行.结果表明,少量La2O3助剂(La/Fe≤0.01,原子比)的加入显著降低了Fe2O3颗粒大小,增加了催化剂的比表面积和分散度,有利于碳化铁的形成,从而导致费-托合成催化活性的提高.随者La2O3含量的进一步增加(La/Fe≥0.02),催化剂表面大量La2O3的覆盖和LaFeO3化合物的形成降低了铁碳化物的形成,反应活性反而降低.因此,最适宜的La2O3含量为La/Fe=0.01.La2O3的加入提高了甲烷的选择性,抑制了C5+碳氢化合物的形成.
A series of La2O3-promoted precipitated iron catalysts(100Fe/2.8Si/nLa,n=0.0.5,1,2,and 4,atomic ratio)were prepared and characterized by in situ X-ray diffraction,CO temperature-programmed reduction,and N2 adsorption-desorption.The catalytic performance for Fischer-Tropsch synthesis was studied in a fixed-bed reactor.It was found that the addition of a small amount of La2O3(La/Fe≤0.01)gave a large decrease in the particle size of Fe2O3,which increased the specific surface area and dispersion of the catalysts.This also favored the formation of iron carbides,which gave a high cataiytic activity in Fischer-Tropsch synthesis.With increasing La2O3 content(La/Fe≥0.02),a high La2O3 coverage and the formation of a LaFeO3 compound decreased the formation of iron carbides,and the reaction activity decreased.The optimum La2O3 content was La/Fe=0.01.The addition of La2O3 increased the selectivity for methane and suppressed the formation of C5+hydrocarbons.
参考文献
| [1] | Rao V U S;Stiegel G J;Cinquegrane G J;Srivastava R D .[J].Fuel Processing Technology,1992,30:83. |
| [2] | 吴春来.煤炭间接液化技术及其在中国的产业化前景[J].煤炭转化,2003(02):17-24,33. |
| [3] | Jin Y M;Datye A K .[J].Journal of Catalysis,2000,196:8. |
| [4] | Egiebor N O;Cooper W C .[J].Canadian Journal of Chemical Engineering,1985,63:81. |
| [5] | Bukur D B;Lang X;Mukesh D;Zimmerman W H,Rosynek M P,Li C .[J].Industrial and Engineering Chemistry Research,1990,29:1588. |
| [6] | Barranlt J;Guilleminot A;Achard J C;Paul-Boncour V,Percheron-Guegan A .[J].Applied Catalysis,1986,21:307. |
| [7] | Gelsthorpe M R;Mok K B;Ross J R H;Sambrook R M .[J].Journal of Molecular Catalysis,1984,25:253. |
| [8] | Schaper H;Doesburg E B M;De Korte P H M;Van Reijen L L .[J].Applied Catalysis,1985,14:371. |
| [9] | Chen Y W;Goodwin J G .[J].React Kiner Catal Lett,1984,26:453. |
| [10] | Haddad GJ.;Goodwin JG.;Chen B. .CHARACTERIZATION OF LA3+-PROMOTED CO/SIO2 CATALYSTS[J].Journal of Catalysis,1996(1):43-51. |
| [11] | Wang D Z;Cheng X P;Huang Z E;Wang X Z,Peng S Y .[J].Applied Catalysis,1991,77:109. |
| [12] | Pour A N;Shahri S M K;Bozorgzadeh H R;Zamani Y,Tavasoli A,Marvast M A .[J].Applied Catalysis A:General,2008,348:201. |
| [13] | Haddad G J;Chen B;Goodwin J G Jr .[J].Journal of Catalysis,1991,161:274. |
| [14] | 熊建民,丁云杰,王涛,吕元,朱何俊,罗洪原,林励吾.La2O3助剂对Co/AC催化剂上费-托合成反应性能的影响[J].催化学报,2005(10):874-878. |
| [15] | Gallaher G;Goodwin J G Jr;Huang C S;Houalla M .[J].Journal of Catalysis,1991,127:719. |
| [16] | Ledford J S;Houalla M;Petrakis L;Hercules D M.Delmon B.Preparation of Catalysts Ⅳ[M].Amsterdam:Elsevier Science,1987:433. |
| [17] | Anderson R B;Emmett P H.Catalysis Ⅳ[M].New York:Reinhold,1956:46. |
| [18] | Rao V U S;Gormley R J;Shamsi A;Petrick T R,Stencel J M,Schehl R R,Chi R D H,Obermyer R T .[J].Journal of Molecular Catalysis,1985,29:271. |
| [19] | Hadjigeorghiou G A;Richardson J T .[J].Applied Catalysis,1986,21:37. |
| [20] | Mok K B;Ross J R H;Sambrook R M .[J].Studies in Surface Science and Catalysis,1983,16:291. |
| [21] | Bian G Z;Oonuki A;Koizumi N;Nomoto H,Yamada M .[J].Journal of Molecular Catalysis,2002,186:203. |
| [22] | 周钰明;丁莹如.[J].催化学报,1991(12):167. |
| [23] | Hayakawa H;Tanaka H;Fujimoto K .[J].Applied Catalysis,2006,310:24. |
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