Cerium impregnation

Sulphate and Cerium Impregnated Ti/Zr02 as Heterogeneous Catalyst for Glycerol Esterification... 

Cerium Impregnation. All of the above spinels were impregnated(1) by cerium nitrate hexahydrate. A portion (87.7 g) of the spinel prepared by any of the above methods was impregnated with a solution containing 42.9 g of 70% Ce(N03)3.6H20 (Ce02 content 28.7%) and 40 g water. This material was dried at 120°C for 3 h and calcined at 700°C for 1 h. 

The ratio of total cerium and cerium exchanged into zeolite decreases from cerium impregnated to cerium exchanged. The precipitated catalysts lead to intermediary systems between IMP and EX catalysts, showing exchanged and superficial cerium species. 

Isopropylation of Naphthalene at 300°C and Cracking of 1,3,5-Triisopropylbenzene at 350°C over H-Mordenites and Cerium Impregnated Mordenite [Sugi et al., 1994a 10m et al., 1995]. 

A. Kato, G. Seo and C. Pak. Cerium Impregnated H-Mordenite as a Catalyst for Shape-Selective Isopropylation of Naphthalene. Selective Deactivation of Acid Sites on the External Surface. Appl. Catal. A General, 1995b, 131, 15-32. 

Nitrate. Cerium(III) nitrate hexahydrate [10294-41 -4] Ce(N03) 6H20, is a commercially available soluble salt of cerium, and because of ready decomposition to the oxide, it is used, for example, when a porous sohd is to be impregnated with cerium oxide. The nitrate is very soluble in water, up to about 65 wt %. It is also soluble in a wide range of polar organic solvents such as ketones, alcohols, and ethers. 

A washcoat, which provides a high surface area onto which the active catalyst is impregnated. The washcoat typically consists of a mixture of zirconium, cerium and aluminium oxides. Apart from providing high surface area the washcoat also acts as an oxygen storage system (see below). 

Ronning, Holmen, and coworkers—Ce doping of Cu/Zn/Al catalysts improves stability. Ronning et al,339 explored the impact of ceria addition to Cu/ZnO catalysts. Catalysts were prepared by co-precipitation of Cu, Zn, and Al from their corresponding nitrates. Ceria was incorporated into the catalyst by impregnation of cerium nitrate either before or after calcination (6 hours at 350 °C or 400 °C). The chemical compositions of the resulting catalysts are reported in Table 62. 

Rare Earths and Alumina. A much easier and cheaper way of getting the SO2 removal enhancement from rare earths that was observed with the well-exchanged rare earth Y zeolite was to add rare earths, especially cerium, by direct impregnation to high alumina cracking catalyst (24). 

Thorium nitrate is a reagent for measuring fluorine and for making thori-ated tungsten filaments. Thorium nitrate containing 1% cerium nitrate is the impregnating liquid in making incandescent gas mantles. 

Chromium(III) and cerium(IV) impregnated Nafion K (a perfluorinated sulfonic acid resin) were used as catalysts f°r the themoselective oxidation of a variety of alcohols using TBHP or NaBr03 as tlie oxy9en donor A e.g. 

Cerium (TV) ammonium nitrate (CAN)37 and a cerium (TV) impregnated resin38 are able to catalyze the selective oxidation of secondary alcohols with sodium bromate (NaBrOi). Stoichiometric cerium bromate— CelBrCb h, prepared in situ from barium bromate and cerium (III) sulfate, is also able to perform selective oxidations of secondary alcohols.39... 

M.B. Mitchell et al., Decomposition of dimethyl methylphosphonate (DMMP) on supported cerium and iron co-impregnated oxides at room temperature. J. Phys. Chem. B 107, 580-586 (2003)... 

Mitchell MB, Sheinker VN, Tesfamichael AB, Gatimu EN, Nunley M (2003) Decomposition of Dimethyl Methylphosphonate (DMMP) on Supported Cerium and Iron Co-Impregnated Oxides at Room Temperature, J Phys Chem B 107 580-586... 

Cerium dioxide is preferred over other oxides because platinum is expensive and vanadium and iron oxides are poisons for FCC catalysts. Usually an aqueous solution of a cerium salt is used to impregnate a spinel base which is then calcined to obtain the Ce02 active form. We have found that a 10 to 12% Ce02 is sufficient for effective S02 oxidation(1). 

Catechols and hydroquinones can be converted (91-98%) into quinones by cerium(IV) salts coated onto silica as free-flowing yellow powder from impregnation with cerium(IV) ammonium nitrate. This reaction is usually performed in the presence of magnesium sulfate. The same (NH4)2Ce(N03)6 SiQ2 reagent in the dry state effects oxidative nitrations of arenes. For example a-mq>hthol is converted to the Orth) (42%) and the para (38%) nitro compounds, while its metiiyl or ethyl ethers give exclusively the para nitration product (equation 4). In solution, the products are cmtaminated with the products of dinitration and of oxidation into quinones. ... 

The next series of experiments was carried out using additionally cerium nitrate as stabilising agent (Table 3, samples 1-16) In the first group of experiments (1-4) alumina precursors shaped with nitric acid and calcined, D1 at 650 C and D3 at 850 °C) were impregnated using cerium nitrate solution... 

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