Catalysis by shapely nanocrystals of the Ce1−xYbxO2−x/2 mixed oxides — Synthesis and phase stability

Solvothermal Synthesis Routes to Substituted Cerium Dioxide Materials

“…An additive that has been well established to affect crystal morphology in hydrothermal formation of cerium oxides is Na 3 PO 4 •12H 2 O. Xu et al found for yttrium substitution that octahedral crystals were produced but with surface nanorods with increasing addition of sodium phosphate [114]. The same octahedral crystal morphology was found by Małecka et al, who studied the formation of ytterbium-substituted CeO 2 [103,115], Roh et al, who examined europium substitution [116], Bo et al for Er-CeO 2 [117] and Yang et al, who prepared erbium-substituted materials, some of which were co-substituted with lithium, Figure 15, where morphology is maintained even after a high-temperature annealing of 800 • C [118]. Małecka also observed that rod-shaped crystals were found at high concentrations of Na 3 PO 4 •12H 2 O [115].…”

“…who prepared erbium-substituted materials, some of which were co-substituted with lith ium, Figure 15, where morphology is maintained even after a high-temperature annealin of 800 °C [118]. Małecka also observed that rod-shaped crystals were found at high con centrations of Na3PO4•12H2O [115]. The octahedral morphology, bounded by {111} faces is known to be a stable form for large crystals of CeO2 itself [119], and while earlier wor showed the effectiveness of Na3PO4 as a mineraliser for growth of octahedral nanocrystal of CeO2, the mechanism of this precise morphological control has not been established beyond discussion of how it might control pH and affect the dissolution-recrystallisatio processes leading to crystallisation [120].…”

“…Xu As well as conventional heating, microwaves have been used to facilitate solvothermal crystallisations of rare earth-substituted cerias. The advantage here lies in the short reaction times, from a few hours down to just a few minutes [102,103,115,[121][122][123]128,[142][143][144][145][146].…”

“…Applications of rare earth-substituted ceria materials span the types of fields expected for these materials, from oxide ion conductors in solid oxide fuel cells, where the enhanced sinterability of fine powders into ceramics is beneficial [136,137,143,149,150], to catalysts for CO and soot oxidation, where the high surface and exposure of specific crystal faces may offer some benefits [103,105,107,108,113,115,132,133,135,[150][151][152][153]. Photocatalytic properties are of increasing focus for degradation of pollutants or organic transformations, and some of the rare earth-substituted materials have been screened for these applications [101,124,141,154].…”

NAP-XPS and In Situ DRIFTS of the Interaction of CO with Au Nanoparticles Supported by Ce1–xEuxO2 Nanocubes

“…At first, Eu 3+ is well soluble in ceria. Doping of ceria with Eu creates the single-phase Ce 1– x Eu x O 2 solid solution in a wide range of Eu concentrationsup to x > 0.30. , Second, contrary to for example Yb 3+ , Eu 3+ has good solubility in ceria even under an extremely strongly base medium of MWHT synthesis, necessary for ceria nanocubes . It allowed us to investigate the effect of Eu doping on the morphology, structure, and functional properties of ceria-based materials in a wide range of Eu concentrations.…”