A series of cerium modified Cr/Ti-PILC catalysts were evaluated, which showed a remarkable increase in the activity of NO oxidation. The aim of this novel design was to investigate the mechanism of cerium modification over the Cr/Ti-PILC catalyst. Physicochemical characteristics were investigated in detail by various techniques such as BET, TPD (NO and O₂), XPS, PL, EPR and DRIFTS. The analysis results demonstrated that cerium modification could facilitate the generation of oxygen vacancy via charge transfer, promote the formation of surface superoxide ions (O₂⁻), and increase the amount of surface nitrates. Furthermore, the original oxidation pathway of Cr/Ti-PILC was maintained by cerium modification. The experimental results showed that the NO conversion of CrCe(0.25)/Ti-PILC catalyst was increased to nearly 66.9% at 300 °C.