通过采用不同金属催化剂进行乙烯催化裂解制备了具有不同微观结构的纳米炭纤维.利用纳米二氧化硅负载的铁、镍以及铁镍合金催化剂在适当的反应条件下分别制备了管状、实心鱼骨状以及空心鱼骨状的纳米炭纤维.由于金属催化剂与纳米二氧化硅间的强相互作用导致在低反应温度下也能达到高的反应活性,所以能够合成出高收率、小直径而且分布均匀的纳米炭纤维.不同结构的纳米炭纤维归因于金属催化剂的不同分散性以及不同的生长机理.通常利用铁催化剂进行乙烯裂解制备纳米炭纤维需要高于650℃,但是在我们的实验中发现500℃低温下利用纳米二氧化硅负载的铁催化剂进行乙烯裂解就能够合成出管状纳米炭纤维.
Carbon nanofibers (CNFs) with various structures were selectively synthesized through the catalytic pyrolysis of ethylene using non-supported and SiO2-supported metals (such as iron, nickel, iron/nickel alloy). Tubular, solid herringbone and hollow herringbone structures were obtained by using SiO2-supported Fe, Ni and Fe-Ni catalyst, respectively. Uniform CNFs with small diameter and high yield were synthesized using SiO2-supported catalyst because of the strong metal-support interaction, which results in high reactive activity at relatively a low temperature. The different structures of the resultant CNFs were ascribed to the dispersion of the metal catalyst and the different growth mechanisms. Normally Fe catalyst displays poor activity for the synthesis of CNFs by CVD of ethylene even at high temperature up to 650 ℃. However, tubular CNFs were prepared at a very low temperature of 500 ℃ by using SiO2-supported iron catalyst in our experiments.
参考文献
[1] | Pederson M R;Broughton J Q .Nanocapillarity in fullerene tubies[J].Physical Review Letters,1992,69(18):2689-2694. |
[2] | Mintmire J W;Dunlap B I;White C T .Are fullerene tubules metallic[J].Physical Review Letters,1992,68(05):631-634. |
[3] | Hamada N;Sawada S;Oshiyama A .New one-dimensional conductors:Graphitic microtubules[J].Physical Review Letters,1992,68(10):1579-1581. |
[4] | Iijima S .Helical mocrotubles of graphitic carbon[J].Nature,1991,354(6348):56-58. |
[5] | Yudasaka M;Komatsu T;Ichihashi T et al.Pressure dependence of the structures of carbonaceous deposits formed by laser ablation on targets composed of carbon,nickel and cobalt[J].Journal of Physical Chemistry B,1998,102(25):4892-4896. |
[6] | 曹宗良,王健农,丁冬雁,戴杰华,余帆.化学气相沉积法快速生长定向纳米碳管[J].新型炭材料,2003(01):48-52. |
[7] | BakerRTK .Catalytic growth of carbonfilaments[J].Carbon,1989,27(03):315-323. |
[8] | 郑瑞廷,程国安,赵勇,刘华平,梁昌林.乙炔催化裂解制备碳纳米带及其结构表征[J].新型炭材料,2005(04):355-359. |
[9] | 雷中兴,刘静,王建波,李轩科,汪厚植.催化剂结构与形态对碳纳米管生长的影响[J].新型炭材料,2003(04):271-276. |
[10] | 朱东波,黄启忠,李晔.Fe催化PAN炭纤维原位生长纳米炭纤维[J].新型炭材料,2002(03):66-69. |
[11] | Marjolein L. Toebes;Johannes H. Bitter;A. Jos van Dillen;Krijn P. de Jong .Impact of the structure and reactivity of nickel particles on the catalytic growth of carbon nanofibers[J].Catalysis Today,2002(1):33-42. |
[12] | M.Perez-Cabero;E.Romeo;C.Royo;A.Monzon;A.Guerrero-Ruiz;I.Rodriguez-Ramos .Growing mechanism of CNTs:a kinetic approach[J].Journal of Catalysis,2004(1):197-205. |
[13] | Young Joon Yoon;Hong Koo Baik .Catalytic growth mechanism of carbon nanofibers through chemical vapor deposition[J].Diamond and Related Materials,2001(3 Pt.3):1214-1217. |
[14] | Park C.;Baker RTK. .Carbon deposition on iron-nickel during interaction with ethylene-hydrogen mixtures[J].Journal of Catalysis,1998(2):361-374. |
[15] | Colin Park;Mark A. Keane .Controlled Growth of Highly Ordered Carbon Nanofibers from Y Zeolite Supported Nickel Catalysts[J].Langmuir: The ACS Journal of Surfaces and Colloids,2001(26):8386-8396. |
[16] | Paul E.Anderson;Nelly M.Rodriguez .Influence of the Support on the Characteristics of Carbon Nanofibers Produced from the Metal-CatalyzedDecomposition of Ethylene[J].Chemistry of Materials,2000(3):823-830. |
[17] | Willems I. .Control of the outer diameter of thin carbon nanotubes synthesized by catalytic decomposition of hydrocarbons[J].Chemical Physics Letters,2000(1/2):71-76. |
[18] | Hernadi Klara. .Production of nanotubes by the catalytic decomposition of different carbon-containing compounds[J].Applied Catalysis, A. General: An International Journal Devoted to Catalytic Science and Its Applications,2000(2):245-255. |
[19] | Park C.;Baker RTK.;Rodriguez NM. .CARBON DEPOSITION ON IRON-NICKEL DURING INTERACTION WITH CARBON MONOXIDE HYDROGEN MIXTURES[J].Journal of Catalysis,1997(1):212-227. |
[20] | Yan Song;Wenming Qiao;Seong-Ho Yoon.Structural change of carbon nanofibers by KOH activation[A].Providence,Rhode Island,USA,2004 |
[21] | Kim M S;Rodriguez N M;Baker R T .The role of interfacial phenomena in the structure of carbon deposits[J].Journal of Catalysis,1991,134(01):253-268. |
[22] | Tauster S J;Fung S C;Garten R L .Strong metal-support interactions.Group 8 noble metals supported on titanium dioxide[J].Journal of the American Chemical Society,1978,100(01):170-175. |
[23] | Vander Wal R L;Ticich T M;Curtic V E et al.Substratesupported interactions in metal-catalyzed carbon nanofiber growth[J].Carbon,2001,39(15):2277-2289. |
[24] | Davis S C;Klabunde K J .Unsupported small metal particles:preparation,reactivity,and characterization[J].Chemical Reviews,1982,82(02):153-208. |
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