A highly reactive catalyst for CO oxidation: CeO2 nanotubes synthesized using carbon nanotubes as removable templates

In this work, the nanocomposites, carbon nanotubes (CNTs) coated with nanosized ceria, were prepared by a facile solvothermal method. The obtained nanocomposites have a dense overlayer which is made of nanoparticles with the diameter of ∼10 nm. Ceria nanotubes with a porous and hollow structure were fabricated by the removal of CNTs, which possess high surface area and remarkable thermal stability. The products were characterized by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The parameters affecting the formation of CeO2 nanotubes were discussed in details. The key steps involved in the formation of the CeO2 nanotubes are solvothermal modifications of CNTs and controlled calcinations. CeO2 nanotubes have an excellent catalytic performance for the CO oxidation. The remains of the templates in the CeO2 nanotubes are considered to play an important part in the enhanced catalytic activity for the formation of CeO2−xCx.