Catalytic decomposition of light alkanes, alkenes and acetylene over Ni/SiO2
Catalytic decomposition of light alkanes, alkenes and acetylene over Ni/SiO2
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DOI：
10.1016/s0926-860x(00)00831-0
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发表时间：
2001-03
影响因子：
5.5
通讯作者：
K. Otsuka;Shoji Kobayashi;S. Takenaka
中科院分区：
文献类型：
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作者：
K. Otsuka;Shoji Kobayashi;S. Takenaka
研究了不同烃类（CH_4、C_2 H_6、C_2 H_4、C_2 H_2、C_3 H_8和C_3 H_6）在Ni（5 wt.%）/ SiO2催化剂进行。碳氢化合物的初始分解速率、分解动力学曲线和沉积碳加氢生成甲烷的动力学曲线取决于碳氢化合物的类型。此外，Ni/SiO2催化剂的催化寿命还与烃类的种类有关，即催化寿命由大到小的顺序为烷烃>烯烃>乙炔。用扫描电镜和拉曼光谱对催化剂上沉积的碳进行了表征。烷烃、烯烃和乙炔的沉积碳形貌不同，甲烷为锯齿状纤维结构，烯烃和乙炔为卷曲状纤维结构。沉积炭的拉曼光谱表明，沉积炭的石墨化程度由高到低的顺序为烷烃>烯烃>乙炔。这些结果表明，烷烃、烯烃和乙炔在催化剂上的裂解机理和碳纤维的生长机理不同。
The decomposition of different hydrocarbons (CH4, C2H6, C2H4, C2H2, C3H8, and C3H6) over Ni (5wt.%)/SiO2catalysts was carried out. The initial rates of decomposition of the hydrocarbons, the kinetic curves of the decomposition and the kinetic curves of the hydrogenation of deposited carbon into methane depended on the types of hydrocarbons. In addition, the catalytic life of the Ni/SiO2catalyst was also dependent on the types of hydrocarbons, i.e. the life was longer according to the order, alkanes>alkenes⪢acetylene. The carbons deposited on the catalyst were characterized by SEM and Raman spectroscopy. The appearances of the deposited carbons were different among alkanes, alkenes, and acetylene, i.e. a zigzag fiber structure from methane, and a rolled fiber structure from alkenes and acetylene. From Raman spectra of the deposited carbons, it was found that the degree of graphitization of deposited carbon was higher in the order, alkanes>alkenes>acetylene. These results suggest that the mechanism of decomposition of hydrocarbons and the growth mechanism of carbon fibers on the catalyst were different among alkanes, alkenes and acetylene.