Synthesis and Catalysis of Location-Specific Cobalt Nanoparticles Supported by Multiwall Carbon Nanotubes for Fischer鈥揟ropsch Synthesis

详细信息    查看全文

• 作者：Yuan Zhu ; Yingchun Ye ; Shiran Zhang ; Mark E. Leong ; Franklin (Feng) Tao
• 刊名：Langmuir
• 出版年：2012
• 出版时间：May 29, 2012
• 年：2012
• 卷：28
• 期：21
• 页码：8275-8280
• 全文大小：392K
• 年卷期：v.28,no.21(May 29, 2012)
• ISSN：1520-5827

文摘

Cobalt nanoparticles located on the concave internal surface of multiwalled carbon nanotubes (Co-in-MW-CNTs) and the convex external surface of MW-CNTs (Co-on-MW-CNTs) were synthesized. Their catalytic performances in Fischer鈥揟ropsch synthesis (FTS) were investigated. A correlation between the location, pretreatment, and surface chemistry of the cobalt nanoparticles and the catalytic selectivity in FTS was built. It is found that the selectivity in production of C₅₊ molecules through FTS on cobalt catalysts supported by MW-CNTs depends on activation temperatures and surface chemistry of the cobalt nanoparticles. A pretreatment at 300 掳C in H₂ flow results in a different surface chemistry for Co-in-MW-CNTs than for Co-on-MW-CNTs, which leads to a difference in selectvity to the production of C₅₊ molecules. Pretreatment at a relatively high temperature, 400 掳C, in H₂ flow produces completely reduced Co nanoparticles in Co-in-MW-CNTs and Co-on-MW-CNTs. There is no signifcant difference in catalytic selectivity between the two catalysts upon pretreatment at 400 掳C. The absence of a significant difference in catalytic selectivity of metallic Co-on-MW-CNTs and metallic Co-in-MW-CNTs suggests that the electronic effect of the MW-CNT support does not significantly affect the C₅₊ selectivity of cobalt catalysts in FTS.