Three-dimensionally ordered macroporous (3DOM) Au/CeO2 catalysts with controlled pore sizes are successfully created via a colloidal crystal template method, and their enhanced catalytic performance for formaldehyde oxidation is systematically investigated for the first time in this paper. The resulting Au/CeO2 catalysts possess well-defined 3DOM structures with adjustable pore sizes from 80 to 280 nm, having interconnected networks of spherical voids. Due to the uniform macroporous structures leading to good distribution of catalytic species of Au nanoparticles with less aggregation, the 3DOM Au/CeO2 catalysts are expected to have enhanced capability for formaldehyde catalytic oxidation. The formaldehyde oxidation tests reveal that the 3DOM Au/CeO2 catalysts exhibit superior catalytic activity with 100% formaldehyde conversion at similar to 75 degrees C, a much lower temperature than previously reported powder Au/CeO2 catalysts. The superior performance of 3DOM Au/CeO2 catalysts for formaldehyde oxidation makes them potentially applicable to in-door formaldehyde decontamination and industrial catalysis. (C) 2009 Elsevier B.V. All rights reserved.