Effect Of CeO₂ Supports On The Performance Of Pt/CeO₂ Catalysts For CO Oxidation

CeO₂ is an excellent redox support that having unique oxygen storage capacity?OSC?,which contributes to enhance the interaction with noble metal.The supported precious metal catalysts exhibit superior low-temperature catalytic performance and are extensively used in the automotive exhaust treatment catalysts.However,the poor stability of CeO₂ leads to the sintering of noble metal at elevated temperature,which reduces the utilization of noble metal and inhibits the development of the supported noble metal catalysts.Therefore,the investigation on how to improve the stability of supports and elevate the dispersion of noble metal is the developing trends in the automotive exhaust treatment field.In this work,a series of CeO₂ supports with different physical structure and chemical properties were obtained by adding surfactant at different synthesis steps.The effect of CeO₂ supports on the interaction between Pt and CeO₂ was researched.The structure and redox property of these samples were characterized by N₂adsorption,XRD,H₂-TPR,DOSC technologies.The dispersion and states of Pt were characterized by CO chemisorption and CO-DRIFTS,respectively.The results indicate that adding surfactant before spray-drying contributes to enhancing the hydrothermal stability of CeO₂.It also facilitates more active oxygen species formation with superior activity.The interaction between Pt and CeO₂ is enhanced with more active oxygen on the surface of CeO₂.This improves the dispersion and stability of Pt,and contributes to enhancing the catalytic performance.