The synthesis of Pt-supported catalysts with high stability faces an enormous challenge, especially for applications in high-temperature environments. Here we attempt to improve the catalytic activity and thermal stability of Pt-supported catalyst via modulating Ce/Zr molar ratio. The crystalline structure, texture and metal dispersion of the Pt/CexZr1-x samples were studied by XRD, Raman, XPS, HRTEM and H2-TPR. The results indicate that decreasing Ce/Zr molar ratio can improve the thermal stability, the reducibility of surface lattice oxygen of the catalyst, and enhance the oxygen vacancy content. On the contrary, a higher Ce/Zr molar ratio facilitates the interaction between Pt and CeO2 and inhibits the growth of Pt particles thereby maintaining high Pt dispersion. The Pt/CexZr1-x catalysts with Ce/Zr molar ratio of ∼1.0 might exhibited the best overall catalytic performance within long-term use. The effect of the valence state of Pt on catalytic activity is greater than that of the Pt dispersion. Our findings contribute to a depth understanding of Pt/CeZr catalysts and provide insights into the design of more efficient and durable catalysts for automotive exhaust purification.
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