Effect of different catalyst supports on the (n,m) selective growth of single-walled carbon nanotube from Co-Mo catalyst

Bo Wang, Yanhui Yang, Lain-Jong Li, Yuan Chen*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

60 Scopus citations

Abstract

Co-Mo catalysts supported on four different high surface area oxides (SiO2, Al2O3, MgO, and TiO2) were evaluated to investigate the (n,m) selectivity control in single-walled carbon nanotube (SWCNT) synthesis. Results from Raman spectroscopy and thermogravimetric analysis showed that Co-Mo catalysts supported on SiO 2 and MgO possessed good selectivity toward SWCNTs, while photoluminescence and ultraviolet-visible-near-infrared spectroscopy results indicated that these two catalyst supports induced the same (n,m) selectivity to near-armchair tubes, such as (6,5) and (7,5) tubes. Catalysts supported on TiO2 produced a mixture of multi-walled carbon nanotubes (MWCNTs) and SWCNTs, whereas catalysts supported on Al2O3 mainly grew MWCNTs. Characterization of catalysts by ultraviolet-visible diffuse reflectance spectroscopy suggested that the surface morphology of metal clusters over different supports was not directly responsible for the (n,m) selectivity. Analysis of monometallic (Co or Mo) and bimetallic (Co-Mo) catalysts using temperature program reduction demonstrated that catalyst supports changed the reducibility of metal species. The interaction between supports and Co/Mo metals perturbed the synergistic effect between Co and Mo, leading to the formation of different metal species that are responsible for the observed distinction in SWCNT synthesis.

Original languageEnglish (US)
Pages (from-to)3285-3295
Number of pages11
JournalJournal of Materials Science
Volume44
Issue number12
DOIs
StatePublished - Jun 1 2009

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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