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We have developed a magnesia (MgO)-supported iron-copper (FeCu) catalyst to accomplish the growth of single-walled carbon nanotubes (SWNTs) using carbon monoxide (CO) as the carbon source at ambient pressure. The FeCu catalyst system facilitates the growth of small-diameter SWNTs with a narrow diameter distribution. UV-vis-NIR optical absorption spectra and photoluminescence excitation (PLE) mapping were used to evaluate the relative quantities of the different (n,m) species. We have also demonstrated that the addition of Cu to the Fe catalyst can also cause a remarkable increase in the yield of SWNTs. Finally, a growth mechanism for the FeCu-catalyzed synthesis of SWNTs has been proposed.

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We report the structure and stability of hydroxylated (1 h11) and (1 h01) surfaces for a water coverage ranging from 0.25 to 1. For the (1 h11) surface water dissociated at low coverage (θ ) 0.25), whereas both dissociated and molecular species coexisted at higher coverage. For the (1 h01) surface molecular adsorption was only observed at the highest coverages (θ ) 0.75 and θ ) 1). The calculated adsorption energy for (1 h11) ranged from -1.20 to -0.83 eV for θ ) 0.25 and θ ) 1, respectively. For the (1 h01) surface the adsorption energies ranged from -1.50 to -1.21 eV for θ ) 0.25 and θ ) 1, respectively. The 1-, 2-, and 3-fold coordinated hydroxyl groups were present in our models. Their structure, energetics, and vibrational frequencies were calculated by ab initio techniques and agreed with in situ infrared spectroscopic measurements. The simultaneous presence of hydroxyl groups of different coordination was concluded from both theoretical and experimental results.