Platinum is commonly used as a catalyst for the oxidation of NO in exhaust gas purification systems. However, in addition to its high cost, the intrinsic NO + O → NO₂ reaction is endothermic and the rate-limiting O_2,gas dissociative adsorption is activated on Pt(111). In this paper, we show for the first time that the pseudomorphic Pt monolayer on 3d transition metals promotes a thermodynamically and kinetically favorable NO oxidation compared to pure Pt. Using density functional theory-based first principles calculations, we show that such results are attributed to the weaker binding of O and NO on the bimetallic surfaces and the change of the binding configuration of NO₂ into a structure that promotes easier N–O bond formation. These results provide insights into the design of low-cost and efficient catalysts for NO oxidation.