Using first-principles density functional theory, we have investigated the catalytic oxidation of CO on Fe-embedded hexagonal boron nitride (h-BN) sheet. Fe atom can be constrained at a boron vacancy site of h-BN sheet with a high diffusion barrier (3.70 eV), and effectively activate the adsorbed O-2 molecule. The reactions between the adsorbed O-2 with CO via both Langmuir-Hinshelwood and Eley-Rideal mechanisms were comparably studied. The reaction proceeds via the more favorable Eley-Rideal mechanism with a two-step route (CO + O-2 -> CO2 + O and CO + O -> CO2). The energy barriers are 0.56 and 0.61 eV, respectively. (C) 2011 Elsevier B.V. All rights reserved.