Support impregnation

Today the most efficient catalysts are complex mixed metal oxides that consist of Bi, Mo, Fe, Ni, and/or Co, K, and either P, B, W, or Sb. Many additional combinations of metals have been patented, along with specific catalyst preparation methods. Most catalysts used commercially today are extmded neat metal oxides as opposed to supported impregnated metal oxides. Propylene conversions are generally better than 93%. Acrolein selectivities of 80 to 90% are typical. 

Chemistry. The stoichiometric equations pertinent to the vapor-phase hydration of ethylene over a catalyst support impregnated with phosphoric acid have been summari2ed (84). 

Lincomycin Hydrochloride Glass column (1.5 M x 3 mm) packed with acid-washed silanised diatomaceous support impregnated with 3% w/w of phenyl methyl silicone fluid (50% of phenyl) (OV-17 is also suitable) and maintained at 260 °C Inlet-port and detector maintained at 260-290 °C Carrier gas Helium-with a flow rate of about 45 ml minute-1. Solutions (1), (2) and (3) Calculate the content of c18h34n2o6s, HC1, H20 in lincomycin hydrochloride BPCRS... 

In supported liquid membranes, a microporous support impregnated with the liquid complexing agent separates the feed and product solutions. In coupled... 

Regarding preparation procedures, the grafting of metal alkoxides on surface hydroxy groups, the co-precipitation procedure and sol-gel synthesis can lead to systems where the mixed oxides can be either close to a classical supported impregnated oxide (for sub-monolayer coverages) or close to solid solutions or multi-layered supported oxides. So the frontier between supported oxides and mixed oxides cannot be well defined. 

The combined influence of calcination temperature (650-850 "C) and long time hydrothermal treatment (200 C, 72h) of alumina support impregnated with TEOS is presented in the end part of Table 1... 

Multiple absorbants have been researched, and they include digitonin, tomatine, sodium cholate (bile salts), and active carbon (45, 47, 50). Most will face severe food regulatory problems. New Zealand (48) performed extensive research on active carbon, carbon impregnated with different metal salts, and inert supports impregnated with selected organic compounds. This technique (active carbon) is... 

Oxygen-sulfur heteroatom exchange has been achieved with 3-methyl-benzene thiazole-2-thione in the presence of trifluoroacetic acid and with l-phenyl-5-mercaptotetrazole. Thiirane can be prepared from oxirane on a support impregnated with alkali metal salts, by decomposition of the dithiocarbon-ate formed with carbon disulfide. A macrocyclic ether, perhydrobenzo-18-crown-6, plays a role in the nucleophilic reaction of oxirane with KCNS, which leads to thiirane in good yield. ... 

X 10 Alumina-washcoat steel-alloy support impregnated with nickel... 

It is possible to redistribute the metal by adding a precipitant to a support that has already been Impregnated. Fig. 13.12 7 shows the effect of adding sodium hydroxide to an alumina support impregnated with one molar nickel nitrate. While the initial impregnation showed a slight increase in nickel concentration near the exterior of the support, the addition of base resulted in a redistribution of the nickel with the formation of essentially a surface coverage of... 

A number of different stationary phases have been used, mostly on a solid support impregnated with potassium hydroxide from very polar ones, such as polyglycols, to non-polar ones, such as silicone rubber. Packed columns have mostly been used, but good separations have also been achieved with capillary columns. 

The stationary phase is an immobilized liquid upon an inert and porous material, which has only a mechanical role of support. Impregnation, the oldest procedure for immobilizing a liquid on a porous material, is a method now abandoned because of the elevated risk of washing out the column, which is called bleeding. 

Most of the silver catalysts used in chemical industry and research are prepared via conventional techniques using preformed microporous or mesoporous inorganic support materials. Examples are the preparation of 5 wt.% Ag/Si02 by support impregnation with silver nitrate or a titania-based catalyst on which silver was deposited by treatment with AgN03 and Na2C03. ... 

A 2 wt% Pd0/AligB4033 catalyst sample was prepared by support impregnation with Pd(N03)2 dissolved in water. After drying and caleination at 500°C in air during 4h (nitrate decomposition), the catalyst was treated at 800°C for 6h in 90 %02 - 10% H2O mixture. A reference PdO/A Os sample containing 2 wt % Pd was prepared following the same procedme for comparison. 

Selectivity is one of the most important goals of the use of heterogeneous catalysis in the production of fine chemicals. Recently, we have reported on new high surface-area supports based on Degussa s pyrogenic TiOg [1]. These catalyst supports, impregnated with precious metals, have... 

Ion-exchange resin methods, which are well known as useful preconcentration methods for trace ions, have some drawbacks slow adsorption and desorption rates, poor selectivity, and requirement for a concentrated solution of electrolyte such as acid, base, or neutral salts for recovery. Chromatographic methods in which solvent extraction procedures have been used in a continuous separation process using inert supports impregnated with the extractants combine many of the advantages of both liquid-liquid extraction and ion-exchange chromatography, which are the two of most im-... 

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