Preparation of Hollow CuO@SiO(2) Spheres and Its Catalytic Performances for the NO + CO and CO Oxidation

The hollow CuO@SiO(2) spheres with a mean diameter of 240 nm and a thin shell layer of about 30 nm in thickness was synthesized using an inorganic SiO(2) shell coating on the surface of Cu@C composite that was prepared by a two-step hydrothermal method. The obtained hollow CuO@SiO(2) spheres were characterized by ICP-AES, nitrogen adsorption-desorption, SEM, TEM, XRD, H(2)-TPR, CO-TPR, CO-TPD and NO-TPD. The results revealed that the hollow CuO@SiO(2) spheres consist of CuO uniformly inserted into SiO(2) layer. The CuO@SiO(2) sample exhibits particular catalytic activities for CO oxidation and NO + CO reactions compared with CuO supported on SiO(2) (CuO/SiO(2)). The higher catalytic activity is attributed to the special hollow shell structure that possesses much more highly dispersed CuO nanocluster that can be easy toward the CO and NO adsorption and the oxidation of CO on its surface.