Facile synthesis of well-dispersed CeO2–CuOx composite hollow spheres with superior catalytic activity for CO oxidation

Abstract

Well-dispersed CeO₂–CuO_x composite hollow spheres have been successfully synthesized through a facile reflux method using carbon spheres as sacrificial templates. The shells of the hollow spheres, ∼40 nm in thickness, consist of self-assembled 10–15 nm sized nanoparticles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study the structural features of the CeO₂–CuO_x composite hollow spheres. X-ray photoelectron spectroscopy (XPS) confirmed that most of the copper element is distributed on the surface of the CeO₂ shell support. The CeO₂–CuO_x composite hollow spheres exhibited enhanced catalytic activity for CO oxidation: complete CO conversion could be obtained at 112 °C. The excellent catalytic activity could be ascribed to the hollow structure, high specific surface area and the strong synergistic interaction between CeO₂ and CuO_x.