Abstract
Ceria-zirconia based mixed oxides (CZs) have been applied in three-way catalysts (TWCs) for their high surface area and oxygen storage capacity (OSC). In this work, enhanced thermal stability of Ce0.33Zr0.55(LaNdY)0.12O2 mixed oxides was realized via a facile and scalable approach, namely, sulfate-aided coprecipitation method was labelled as CZ-S. Sulfate ion (SO42−) was added into raw solution in the form of sulfuric acid and acted as coordination agent. The control sample was prepared by conventional coprecipitation method without sulfuric acid added and labelled as CZ. The promotion effect of sulfate ion was analyzed systematically by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), OSC and hydrogen temperature-programmed reduction (H2-TPR) analysis. XRD and high resolution TEM results reveal that CZ-S have homogeneous distributions of elements. TEM and SEM images show that fresh samples of CZ-S have narrower distributions of grain sizes and larger pore sizes than those of CZ. Through cross analysis of structure and morphology of CZ and CZ-S, we find that the introduction of sulfate ions results in uniform distributions of elements, narrows distributions of grain sizes, and enables the formation of secondary loose packing of sub-particles, which lead to enhanced thermal stability of the samples of CZ-S upon aging process at high temperature. After aging treatment at 1100 °C for 10 h, aged samples of CZ-S present larger specific surface areas and pore volumes than the aged sample prepared by conventional coprecipitation method without sulfate ions added. Furthermore, the aged sample of CZ-S2 (SO42−/Zr = 1) possesses the highest specific surface area of 21.9 m2/g and the biggest pore volume of 0.035 mL/g among all aged samples.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
