Journal ArticleDOI
Continuous hydrothermal synthesis of inorganic materials in a near-critical water flow reactor; the one-step synthesis of nano-particulate Ce1 − xZrxO2 (x = 0–1) solid solutions
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TLDR
In this paper, solid solutions are produced continuously by hydrolysis of mixtures of cerium and zirconium acetate in near-critical water at ca.300°C and 25MPa using a flow reactor.Abstract:
Ce1 − xZrxO2
solid solutions are produced continuously by hydrolysis of mixtures of cerium
ammonium nitrate and zirconium acetate in near-critical water at ca.
300 °C and 25 MPa using a flow reactor. Rapid hydrothermal
coprecipitation leads to nano-particulate Ce1 − xZrxO2
(x = 0–1),
the composition of which is largely determined by the initial relative concentrations
of Ce4+ and Zr4+ ions in the starting solution.
The freshly prepared materials are crystalline, possess very small particle
sizes, and have high surface areas. The effects of calcining the products
in air at high temperature have been studied. Apart from the 1∶1 Ce∶Zr
solid solution, the phases of Ce1 − xZrxO2
remain stable on calcining to 1000 °C, but the particles sinter
and the surface areas decrease significantly. The materials have been characterised
by Powder X-ray Diffraction (PXD), IR and Raman Spectroscopy,
microanalysis, Thermogravimetric Analysis (TGA), X-ray Fluorescence (XRF)
and BET (surface area measurements). In selected cases, high resolution
Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM)
images were recorded to examine the particle morphology.read more
Citations
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References
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Journal ArticleDOI
Ion Product of Water Substance, 0-1000 C, 1-10,000 Bars. New International Formulation and Its Background,
William L. Marshall,E. U. Franck +1 more
TL;DR: In this article, the International Association for the Properties of Steam (IAPS) issued a new international formulation for the ion product of water substance (May 1980), which is represented by an equation, based on density and two quadratic functions of reciprocal absolute temperature, for use from 0 to 1000°C and 1 to 10,000 bars pressure.
Journal ArticleDOI
Modification of the Redox Behaviour of CeO2Induced by Structural Doping with ZrO2
Paolo Fornasiero,Gabriele Balducci,R. Di Monte,Jan Kašpar,Valter Sergo,G. Gubitosa,A. Ferrero,Mauro Graziani +7 more
TL;DR: In this article, the reduction/oxidation behavior of high surface area CeO2 and Ce0.5Zr 0.5O2 mixed oxide is compared, and it is shown that the introduction of ZrO2 into the Ce2 framework with formation of a solid solution strongly modifies the reduction behaviour in comparison to that seen with CeO 2 alone, and that the expansion/contraction of the lattice parameter upon, respectively, reduction andoxidation, detected by X-ray diffraction, is responsible for the textural modification.
Journal ArticleDOI
The Role of Hydrothermal Synthesis in Preparative Chemistry
TL;DR: In this article, the previously common distinction between hydrothermal conditions below and pneumatolytic conditions above the critical point is no longer made, since no discontinuities are observed upon exceeding the critical conditions.
Journal ArticleDOI
Rapid and Continuous Hydrothermal Crystallization of Metal Oxide Particles in Supercritical Water
TL;DR: In this article, a metal salt aqueous solution with preheated water fed from another line was used to produce metal oxide fine particles in less than 2 min. Particle size, morphology, and crystal structure of the obtained metal oxides were examined.