Cerium hydroxide

Cerium(III) chloride is prepared by the reaction of hydrochloric acid with a cerium salt, such as cerium hydroxide or carbonate, followed by crystaUization ... 

Synonyms cerous hydroxide cerium hydroxide cerous hydrate Uses... 

Pour 1 ml of cerium nitrate into a test tube and add a few drops of sodium hydroxide. What happens Write the equation of the reaction. Act on the precipitate with an excess amount of the sodium hydroxide. Does cerium hydroxide react with sodium hydroxide ... 

React the cerium hydroxide precipitate with 1 N solutions of hydrochloric, sulphuric, and nitric acids. Write the equations of the reactions. 

Guillou et al., 1997 Kleinlogel and Gauckler, 2000 Purohit et al., 2001 Trovarelli et al., 1997). The method by annealing of cerium hydroxides or cerium hydroxyl carbonates with special nanostructures is used to obtain ceria nanostructure, which has been discussed above. 

Among the rare earth elements, cerium is an exception. The impurity of CeV04 NPs prepared under high alkaline conditions was Ce02, rather than cerium hydroxides, because Ce(OH)3 was prone for dehydration and oxidation. Chen s)mthesized CeV04 NPs from NH4VO3 and Ce(N03)3 in hydrothermal reactions with different pH (ranging from 9 to 14). The pH value of 12 was shown to be the upper threshold for pure vanadate NPs (Chen 2006). 

Cerium hydroxide was precipitated from cerium(IIl) nitrate solution under stirring for 24 h, followed by drying at 80 °C overnight. RuCI, and formaldehyde... 

Samples of Cu-Ce oxides are prepared by incipient wetness impregnation method. Cerium hydroxide is precipitated by adding cerium nitrate to a concentrated solution of NaOH. The precipitate is thoroughly washed with warm water, filtered and dried at 373 K before its calcination at 673 K for 6 hours in a flow of dry air. Copper nitrate of different amounts is then impregnated, at room temperature, on the oxide support. The samples are dried at 373 K and calcined at 673, 873 or 1073 K for 6 hours in a flow of dry air. Samples are denoted by lCuxCe673, lCuxCe873 and lCuxCel073 where x indicates the atomic ratio of cerium to copper in the solid, and the last number indicates the calcination temperature value of the sample. 

In rats administration of chemicals present in cigarette smoke after exposure to radon and radon daughters resulted in a decrease in the lung cancer latency period when compared to the time-to-tumor induction in animals treated with radon alone. This effect was seen with 5,6-benzoflavon (Queval et al. 1979) and with cerium hydroxide (Chameaud et al. 1974). 

Ordered mesoporous nanocrystalline CeOi was obtained by using silica hard templates.CeCls was incorporated into the mesoporous silica and then converted to cerium hydroxides by reacting with ammonia vapour. Calcination of cerium silica composite and removal of the silica using NaOH solution produced mesoporous CeOi. 

A band at 3500 cm is usually attributed to oxyhydroxy species (cerium hydroxide microphase (654)) or residual bicarbonates (639). In some publications, the band was assigned to type III hydroxyls (117,695,696,698). 

J. H. Tong, H. Y. Xu, D. Wang and Y. Matsumura, Preparation of thin palladium membrane on porous stainless steel support modified with cerium hydroxide, J. Jpn. Pet. Inst., 2004, 47, 64-65. 

Under oxidising conditions, notably associated with deposition of iron hydroxides in the oceans, cerium is oxidised to Ce, with a consequent reduction in radius of 15% (Shannon 1976). This results in the precipitation of cerium hydroxides and phosphates in manganese nodules and a consequent dramatic depletion of Ce, compared to the other lanthanides, in seawater. This property has been used, for example, to estimate paleoredox conditions in ancient oceans. 

An approach to formation of labeled monomers could involve lanthanides (e.g., cerium and yttrium) as labels (P.A. Heiden, personal communication). Rare earth salt such as cerium hydroxide can be reacted directly with a polymerizable monomer or a ligand (to shift the absorption) that is reacted with a polymerizable monomer. This route is illustrated below using cerium(III) acetate hydrate. 

Inorganic additives cerium hydroxide or oxide [41], compounds of pentavalent niobium and tantalum [84], are also used as photostabilizers. 

A fractional precipitation using differences in basicity is difficult but possible. In a solution containing lanthanum, cerium and other light lanthanides, cerium is oxidized to 6 + ion. If ammonia or sodium hydroxide is now added, cerium hydroxide... 

In connection with the above statements a next step has been made in the investigations, namely studying the influence of the Ce and Ce + ions as components of the corrosion medium (O.IN H2SO4) on the anodic behavior of stainless steel. These investigations were provoked by the observed occurrence of cathodic depolarization reaction of Ce + (CeCb) reduction, as a result of which the surface concentration of cerium is decreasing and theoretically it should approach zero value (Stoyanova et al., 2010). For this purpose an inverse experiment was carried out at different concentrations of Ce + ions in the corrosion medium we monitored the changes in the stationary corrosion potential of the thermally treated steel by the chronopotentiometric method. The aim of this experiment was to prove the occurrence of a reversible reaction of reduction of Ce + Ce +- e <-> Ce , (instead of the reaction of hydrogen depolarization), which in its turn creates also the option to form a film (chemically insoluble) of cerium hydroxides/oxides on the active sections of the steel surface. 

When an insoluble hydroxide, such as Ce(OH)j has formed over the surface, the surface becomes less active and thus, the cathodic reaction is modified. That is, the nmnber of exchanged electrons in such a reaction would now range between 2.2 and 3.6 (Boto and Williams, 1977). Taking into account this fact, the values of the pH reached in the cathodic areas are 10.39 and 10.60 for n=2.2 and 3.6, respectively, so the theory is still valid to explain the formation of cerium hydroxide (III). 

The mechanism described by the two works previously mentioned is consistent with the one described by Virtanen et al. (1997) for stainless steel. These authors pointed out that the deposition of cerium hydroxide is incorporated in the surface by local destmction of the oxide film followed by a precipitation of cerium species from the solution, rather than by a diffusion of cerium into an existing film, as the latter would be expected to lead to a higher surface concentration of cerium. 

Stability ranges for aluminium, lanthanum and cerium hydroxides. The pH where cerium peroxo hydroxide (CeOjIOHIj) first precipitates is also indicated (after Yasakau etal. ). 

Tang, C.C., Bando, Y., Liu, B.D. and Golberg, D. (2005) Cerium oxide nanotubes prepared from cerium hydroxide nanotubes. Advanced Materials, 17, 3005-9. 

The reaction of the cerium salt under constant pH (usually 8-9) with precipitants results in the precipitation of cerium hydroxide. Thermal treatment above 300 °C leads to the formation of a nanosized well-crystallized material with a cubic fluorite structure and average particle size 6-10 nm. The BET surface area is in the range 70-120 m g The influence of different precipitants on the properties of ceria has not been studied systematically. 

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