【摘要】 采用浸渍法制备了不同La掺杂量的Ni-SiO2催化剂,研究了La掺杂量对Ni-SiO2催化剂的Ni活性金属粒径、还原性能、甲烷催化裂解寿命以及反应后生成碳纤维的影响。结果表明:La、Ni物质的量比由0增长至0.3时,Ni-SiO2催化剂的寿命显著提高,而当La、Ni物质的量比由0.3增长至0.6时,催化剂寿命在一定程度上略有降低;La、Ni物质的量比由0增长至0.6时,还原后催化剂Ni金属的平均粒径从26.43nm不断降低至10.57nm。不同La掺杂量Ni-SiO2催化剂甲烷催化裂解过程中Ni金属平均粒径变化趋势明显不同,n(La)∶n(Ni)=0的Ni-SiO2催化剂随反应进行Ni金属平均粒径不断降低,而n(La)∶n(Ni)=0.3的Ni-SiO2催化剂随反应进行Ni金属平均粒径则不断升高。碳纤维形态受掺La掺杂量影响较大,随La、Ni物质的量比由0增长至0.3,反应过程中生成的碳纤维管径变粗,而随La、Ni物质的量比由0.3增长至0.6,碳纤维变短。更多还原

【Abstract】 Ni-SiO2 catalysts doped with different contents of La were prepared by impregnation method.The effects of La contents doped in Ni-SiO2 on the Ni particle size,the reducibility of catalysts,the catalytic performance of methane decomposition and the structure of carbon filaments were studied.The results demonstrate that the lifespan of Ni-SiO2 increased continuously when the molar ratio of La/Ni increased from 0 to 0.3,while as the molar ratio of La/Ni increased from 0.3 to 0.6,a downward trend appeared.The Ni particle size decreased from 26.43nm to 10.57nm when the molar ratio of La/Ni increased from 0 to 0.6.The changing tendency of Ni particle size of Ni-SiO2 during methane decomposition was different for Ni-SiO2 with different the molar ratio of La/Ni.The Ni particle size of Ni-SiO2(n(La)∶n(Ni)=0) decreased continuously as methane decomposition proceeded,however,the Ni particle size of Ni-SiO2(n(La)∶n(Ni)=0.3) increased continuously as the reaction proceeded.The structure of the carbon filaments generated during methane decomposition strongly depended on the molar ratio of La/Ni: as the La/Ni increased from 0 to 0.3,the carbon filaments turned thicker,while as the the molar ratio of La/Ni increased from 0.3 to 0.6,the carbon filaments turned shorter.更多还原