Ferrous sulfate catalyst

Although gravimetric methods have been used traditionally for the determination of large amounts of tellurium, more accurate and convenient volumetric methods are favored. The oxidation of teUurium(IV) by ceric sulfate in hot sulfuric acid solution in the presence of chromic ion as catalyst affords a convenient volumetric method for the determination of tellurium (32). Selenium(IV) does not interfere if the sulfuric acid is less than 2 N in concentration. Excess ceric sulfate is added, the excess being titrated with ferrous ammonium sulfate using o-phenanthroline ferrous—sulfate as indicator. The ceric sulfate method is best appHed in tellurium-rich materials such as refined tellurium or tellurium compounds. 

A platinum-iron on silica gel catalyst was prepared by impregnating silica gel (BDH, for chromatographic adsorption) with an aqueous solution of chloroplatinic acid (analytical grade) and sodium hydroxide (analytical grade). The dry product was then impregnated by a ferrous sulfate solution (C.P. grade) and the water was removed in a rotating evaporator. The prepared catalyst contained 1% Pt, 0.7% Fe, and 2% NaOH (by... 

The 10,11-dihydrodiol of MBA was synthesized from MBA by Method III (12). Hydrogenation of MBA over a platinum catalyst took place regiospecifically in the terminal ring to provide 8,9,10,11-tetra-hydro-MBA (75). Treatment of the latter with DDQ furnished 8,9-dihydro-MBA which underwent conversion to the 10,11-dihydrodiol by the usual procedures. Oxidation of MBA with ascorbic acid-ferrous sulfate to afford low yields ( <0.2%) of the five possible di-hydrodiols has also been described (76). 

The chemical method for the determination of the chemical oxygen demand of non-saline waters involves oxidation of the organic matter with an excess of standard acidic potassium dichromate in the presence of silver sulfate catalyst followed by estimation of unused dichromate by titration with ferrous ammonium sulfate. Unfortunately, in this method, the high concentrations of sodium chloride present in sea water react with potassium dichromate producing chlorine ... 

Polymerizations were carried out in a jacketed, 1-gal, stirred, pressure tank reactor. Typical reactions were run by adding water, alcohol, or chain transfer agent, phosphate buffer, and persulfate to the reactor. The reactor was pressurized with CTFE monomer. Sulfite solution was fed at a rate to maintain reaction. Copper and iron ions were used at times as catalysts by adding cupric sulfate or ferrous sulfate.3 The product was filtered, washed with 90 10 water methanol followed with deionized water. The product was dried at 110°C. 

As to catalytic reactions in homogeneous media, Moritz Traube found in his studies of the oxidation of hydrogen iodide by hydrogen peroxide in aqueous solution, that the catalyst ferrous sulfate is activated by copper sulfate (5). As to the magnitude of such effects, Price stated in 1898 (6) that the simultaneous action of iron and of copper compounds on the reaction between persulfate and hydrogen iodide causes an unexpected acceleration of the reaction, which is more than twice as great as the acceleration calculated as an additive effect of the two single catalysts. However, effects were also observed of the opposite kind,... 

The preirradiated foam was treated with monomer solution containing ferrous ammonium sulfate catalyst under the conditions described above, but the nitrogen purge was omitted. The samples were removed from the monomer solution and passed between rubber rollers to remove excess monomer and then placed in an air-tight container. The container was evacuated, and grafting of the monomer-wetted polymer was allowed to proceed in vacuo for about 16 hours at room temperature. 

Ferrocenylacetonitrile, 40, 4S Ferrous sulfate, oxidation ferf-butyl alcohol to a,a,a, a -tetramethyl tetra-methylene glycol by hydrogen peroxide and, 40, 90 Fluoboric acid as catalyst for diazomethane etherifications, 41, 9,10 Formaldehyde, reaction with diethyl malonate to form diethyl bis-(hydroxymethyl)malonate, 40, 27... 

When the powdered coal is mixed intimately with a catalyst such as 1% (of the dry coal) of ferrous sulfate or 0.2% of ammonium molybdate, the oil yield is increased, and its asphaltene content is reduced. 

Benzoquinone [106-51-4], C6H402 (quinone) has been reported as a by-product of benzene oxidation at 410—430°C. Benzene can be oxidized to phenols with hydrogen peroxide and reducing agents such as Fe(II) and Ti(II). Frequendy ferrous sulfate and hydrogen peroxide are used (Fenton s reagent), but yields are generally low (12) and the procedure is of limited utility. Benzene has also been oxidized in the vapor phase to phenol in low yield at 450—800°C in air without a catalyst (13). 

Fur. Fur is bleached to permit dyeing to the desired shade. The coloring matter in fur is usually bleached using hydrogen peroxide stabilized with sodium silicate. For difficult to bleach dark hairs it is necessary to add a step using a reducing agent with a catalyst such as ferrous sulfate. The formula and procedures are the same as those used for wool. 

In fine chemical manufacturing, the application of promoted platinum catalysts is less known. Maxted and Akhar have reported that the addition of stannous, manganous, ceric and ferric chloride to platinum oxide (Adams catalyst) facilitates the hydrogenation of aldehydes, ketones and olefins (ref. 1). The selective hydrogenation of unsaturated aldehydes or ketones to unsaturated alcohols has been achieved by the addition of ferrous sulfate and zinc acetate to platinum catalysts (ref. 2). 

Cyclopentanone has been prepared from adipic acid by distilling the calcium salt,1 heating alone 2 or with acetic anhydride,3 or in the presence of various catalysts such as barium hydroxide,4 thorium oxide,5 manganous oxide,5 uranium nitrate,6 ferrous sulfate 6 and others.7... 

CHS, and nitric oxide (Chap. 15). Radicals have a typical set of reactions in the gaseous state, many will remove thin films of metals from hot glass, and in solution they often can induce polymerization of compounds having carbon-carbon double bonds. Thus, a solution of ferrous sulfate and hydrogen peroxide (such a mixture is called Fenton s reagent) qatalyzes the conversion of acrylonitrile, CH2=CH—CN, to its polymer neither H202 alone nor Fe2+ alone is effective as a catalyst. 

The presence of ferrous salts or ferrous salts with hydroxide ion was also claimed to improve the yields of hydrazines. The shortest reaction time and largest conversion to W/V-di methyl hydrazine was obtained in the presence of 0.5 mmol of ferrous sulfate in the hydrogenation of 15 ml of A-nilrosodi methyl amine over 1 g 5% Pd-C in 135 ml of water at 45°C and 0.28-0.34 MPa H2.212 Under similar conditions, 5% Pd-C containing 5 mmol of sodium hydroxide and 1 mmol of ferrous sulfate per gram of catalyst gave 50% reaction in 57 min, 98.9% N,N-di-methylhydrazine, and a ratio of 41 moles of the hydrazine per mole of amine.213... 

This ring closure takes place readily whenever the carbonyl and amino groups occur in the relative positions shown above. Reduction of o-nitro-phenylacetonitrile by stannous chloride produces indole rather than the corresponding amino aldehyde. The synthesis is most useful for the preparation of indole-2-carboxylic acid by reduction of o-nitrophenyl-pyruvic acid with ferrous sulfate and ammonia or with sodium hydrosulfite. The ethyl ester is obtained by a similar reduction with zinc and acetic acid or by catalytic hydrogenation of ethyl o-nitrophenyl-pyruvate over platinum oxide catalyst. ... 

Chromium compounds increase the activity of platinum catalysts by increasing the electron densities of the active sites. jhe addition of ferrous sulfate, which promotes the hydrogenation of carbonyl groups, and zinc acetate, which inhibits the hydrogenation of double bonds, to platinum gives a catalyst system capable of effecting the selective hydrogenation of an unsaturated aldehyde to an unsaturated alcohoP - (Eqn. 11.12). ... 

In vinyl compound polymerization of vinyl acetate, alcohol, bromide, chloride, or carbonate, ascorbic acid can be a component of the polymerization mixture (733-749). Activators for the polymerization have been acriflavine (734), other photosensitive dye compounds (737,738), hydrogen peroxides (740,741,742), potassium peroxydisulfate (743), ferrous sulfate, and acyl sulfonyl peroxides (747). Nagabhooshanam and Santappa (748) reported on dye sensitized photopolymerization of vinyl monomers in the presence of ascorbic acid-sodium hydrogen orthophosphate complex. Another combination is vinyl chloride with cyclo-hexanesulfonyl acetyl peroxide with ascorbic acid, iron sulfate, and an alcohol (749). Use of low temperature conditions in emulsion polymerization, with ascorbic acid, is mentioned (750,751). Clarity of color is important and impact-resistant, clear, moldable polyvinyl chloride can be prepared with ascorbic acid as an acid catalyst (752) in the formulation. 

Instead of pure maleic acid, 10.6 g. (0.1 mole) of pure benzaldehyde may be used for the standardization. In this case 1 cc. of 0.1 molar ferrous sulfate is added to the mixture of benzaldehyde, alcohol and catalyst before the reduction is started (see Note 13, p. 98). The reduction is complete in fifteen to thirty minutes. 

Favorski rearrangement, 1092, 1202 Fehling solution, 390 Fenton s reagent, see Hydrogen peroxide, with salt or oxide catalysts Ferric chloride, 297, 390-392, 702, 814 anhydrous, 392 Ferrocene, 181, 392 Ferrous chloride, 392 Ferrous sulfate, 393 Fieser reagent, 145 Fieser s solution, 222, 393, 737 Filter aid, see Celite Fischer indole synthesis, 899 Fischer reagent, see Karl Fischer reagent Fisetin, 64... 

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