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Impact of Mo and Ce on growth of single-walled carbon nanotubes by chemical vapour deposition using MgO-supported Fe catalysts

2009; Elsevier BV; Volume: 255; Issue: 16 Linguagem: Inglês

10.1016/j.apsusc.2009.04.017

1873-5584

Abdel-Nasser A. El-Hendawy, Robert J. Andrews, Andrew J. Alexander,

Advancements in Battery Materials

A series of nine catalysts containing Ce/Fe and Mo/Fe at various loadings on MgO supports have been studied as catalysts for chemical vapour deposition (CVD) of single-walled carbon nanotubes (SWCNTs) using a methane carbon source. Our results show that the Ce/Fe system is very suitable as a catalyst that favours SWCNT growth, and we question the special importance that has been attributed to Mo as an additive to Fe-based catalysts for SWCNT growth, as it appears that Ce is equally effective. Our results indicate that dehydroaromatization (DHA) is not a defining step for the growth mechanism, as has been suggested for Mo/Fe systems previously, and show that Ce and Mo do not seriously perturb the well-known Fe/MgO system for growth of high quality SWCNT. Using Raman spectroscopy, we have shown that the Ce/Fe/MgO catalyst system favours growth of SWCNTs with a different distribution of chiralities compared to the analogous Mo/Fe/MgO system.