Catalysts with fast NO oxidation kinetics and moderate adsorption towards NO2 are urgently required for fast selective catalytic reduction of NO. Based on density functional calculations, we report in this work that Au monolayer on WC(0001) (Au/WC) has both high NO oxidation activity and strong adsorption to NO2. The WC substrate shifts the d-band center of Au monolayer to the vicinity of the Fermi level and the binding strength of reactants on Au/WC is consequently enhanced. The rate constants of gas desorption obtained in this work are significantly lower than those of forward reactions, in accordance with previous molecule dynamics simulations. We anticipate that the present results will facilitate the development of high-performance catalysts for NO oxidation.