Surface and Texture Properties of Tb-Doped Ceria-Zirconia Solid Solution Prepared by Sol-Gel Method

The three-way catalysts (TWCs) promoters Ce0.6Zr0.4-xTbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x =0.05 to x =0.15 favors an increase of surface area from 66.8 to 80.4 m2·g−1 compared with the undoped sample Ce0.60Zr0.40O2 65.1 m2·g−1 after calcination at 650 °C. Transmission electron microscopy (TEM) observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce4+ and Tb3+, and Zr existed in the form of Zr4+ on the surface of the samples. The doped samples were homogenous in composition; the introduction of Tb into the CeO2-ZrO2 promoters resulted in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.