Theoretical Studies on Ethanol Dissociation on Iron Nanoparticles in the Early Stage of SWCNT Growth

The ethanol dissociation process on an iron cluster was estimated by nonequilibrium quantum chemical molecular dynamics simulations and static potential energy surface calculations based on the density-functional tight-binding potential. The competition among reaction pathways related to C–H, O–H, C–C, C–O cleavage, and H2 formation were studied. The schematic of ethanol as a carbon source to grow single-walled carbon nanotubes on iron clusters was also predicted. The simulations highlighted the C–O and O–H bond cleavage were more favorable on iron cluster than the other pathways due to the lower barrier and higher exothermicity and C2Hx (x = 4–6) were the major intermediates. The ethanol dissociation pathway on iron catalysts promised the two carbon atoms in ethanol were nearly equivalent and had similar contribution for the further single-walled carbon nanotube growth, consistent with the observation in previous experimental work.