Morphology effect of one-dimensional iron oxide nanocatalysts on Fischer–Tropsch synthesis

Abstract

One-dimensional iron oxide nanocatalysts have been fabricated by a facile, one-step hydrothermal method. The nanotubes show distinguished catalytic activity and selectivity to heavy hydrocarbons compared to other Fe catalyst morphologies. This can be attributed to their shape anisotropy, mesoporous structure and stable chemical phase under reaction conditions. The nanotubes facilitate the formation of active iron carbides unlike nanorods, which further improve the catalytic activity. The nanotubes also show high activity due to the interactions between the inside surface of the cavity and the reactant. Furthermore, the pore structure of the nanotubes would also influence the selectivity. This strategy results in efficient control of the chain length distribution in the Fischer–Tropsch synthesis due to the steric restrictions on the growth of hydrocarbons. To some extent, the morphology-dependent nanocatalysts bridge the gap between real catalysts in practical applications and model catalysts used in surface science.