Low-Temperature Direct Synthesis of Nanoparticles of Fluorite-Type Ceria–Zirconia Solid Solutions by “Forced Cohydrolysis” at 100°C

Preparation and characterization of nanocrystalline, high-surface area CuCeZr mixed oxide catalysts from homogeneous co-precipitation

“…4a is recorded after drying at 100 • C. The characteristic peaks of the fluorite-type structure show that this structure is present already after drying. This is in agreement with Hirano et al [39], who observed the fluorite structure in as-precipitated Ce Zr (hydrous) oxide samples after drying at 60 • C. Lamonier et al [43] made a corresponding observation for Cu Ce mixed oxides dried at 90 • C. No significant change in the fluorite structure can be observed upon calcination (Fig. 4c) and redox treatment (Fig.…”

“…If the structure remains more or less unaffected by varying composition, the molar mass can simply be used to eliminate the mass effect, resulting in a mole-based BET value (m 2 /mole). The BET results obtained by Kapoor et al [37], for mesostructured Ce Zr mixed oxides, and Hirano et al [39], for non-ordered microporous Ce Zr mixed oxides, are useful for exemplifying the effect of the metal composition on the surface area (Fig. 1).…”

“…Incorporation of Zr into the ceria lattice enhances the reducibility of ceria [34][35][36], which may improve the catalytic activity of MMO catalysts relative to single oxides [37,38]. The amount of Zr dopant also affects surface area and crystallite size of the MMO [37,39], in conjunction with the calcination temperature [40]. In addition to its presumed function as an active catalytic species, Cu as a dopant in the fluorite lattice is found to improve the reducibility of ceria [41,42], and affect particle size and surface area [24,43].…”

Preparation of CexZr1−xO2 (x=0.75, 0.62) solid solution and its application in Pd-only three-way catalysts

“…If CeO 2 -ZrO 2 was prepared by coprecipitation using soluble Ce 3+ and Zr 4+ salt, the structural heterogeneity can be aroused [17]. It was possible to induced by the difference of precipitation speed of Ce 3+ and Zr 4+ ion, because of great difference of solubility product between Ce(OH) 3 (1.5 Â 10 À20 ) and Zr(OH) 4 (2 Â 10 À48 ).…”

“…So far, various synthetic routes of CeO 2 -ZrO 2 solid solutions were reported such as high-energy ball milling [13], reverse microemulsion [14], sol-gel techniques [15,16], coprecipitation [17,18], hydrothermal synthesis [19,20] and so on.…”