Vanadium chloride catalyst

Another application of an isomerisation reaction can be found in the production of the third monomer that is used in the production of EPDM rubber, an elastomeric polymerisation product of Ethene, Propene and a Diene using vanadium chloride catalysts. The starting diene is made from vinylnorbomene via an isomerisation reaction using a titanium catalyst. The titanium catalyst is made from tetravalent salts and main group hydride reagents, according to patent literature. 

The vanadium pentoxide catalyst Is prepared as follows Suspend 5 g. of pure ammonium vanadate in 50 ml. of water and add slowly 7 5 ml. of pure concentrated hydrochloric acid. Allow the reddish-brown, semi-colloidal precipitate to settle (preferably overnight), decant the supernatant solution, and wash the precipitate several times by decantation. Finally, suspend the precipitate in 76 ml. of water and allow it to stand for 3 days. This treatment renders the precipitate granular and easy to 6lter. Filter the precipitate with suction, wash it several times with cold 5 p>er cent, sodium chloride solution to remove hydrochloric acid. Dry the product at 120° for 12 hours, grind it in a mortar to a fine powder, and heat again at 120° for 12 hours. The yield of catalyst is about 3 - 5 g. 

Oiganometallic usage is shown in the piepaiation of titanium- oi vanadium-containing catalysts foi the polymerisation of styrene or butadiene by the reaction of dimethyl sulfate with the metal chloride (145). Free-radical activity is proposed for the quaternary product from dimethylaruline and dimethyl sulfate and for the product from l,l,4,4-tetramethyl-2-tetra2ene and dimethyl sulfate (146,147). 

Impurities with catalytic effects—Impurities that act as catalysts, reducing the activation energy of a process, may increase the rate of reaction significantly, even when present in small quantities. The presence of sulfuric acid, for example, increases the rate of decomposition and decreases the observed onset temperature of various isomers of ni-trobenzoic acid [28]. Also, other substances such as NaCl, FeCl3, platinum, vanadium chloride, and molybdenum chloride show catalytic effects. As a result, the decomposition temperature can be lowered as much as 100°C. Catalysts, such as rust, may also be present inadvertently. Some decomposition reactions are autocatalyzed, which means that one of more of the decomposition products will accelerate the decomposition rate of the original substance. 

Table VI summarizes important homogeneous Ziegler catalysts. The best known are the systems based on bis(cyclopentadienyl)titanium(IV), titanium alcoholates, vanadium chloride, or chromium acetylacetonate with trialkylaluminum or alkylaluminum halides.

Ferric chloride hexahydrate Iron pentacarbonyl Palladium diacetate Phosphotungstic acid Vanadium pentoxide catalyst, organic synthesis Boron tribromide Boron trichloride Boron trifluoride Cobalt Mercury acetate (ic) Trimethylsilyl trifluoromethane sulfonate Zinc acetate... 

The most investigated homogeneous catalyst systems are based on bis(cyclopenta-dienyl)titanium(lV), bis(cyclopentadienyl)zirconium(rV), tetrabenzyltitanium, vanadium chloride, and trialkylaluminum or alkylaluminum halides as cocatalysts. Subsequent research on these and other systems with various alkyl groups has been conducted by Patat and Sinn [4], Shilov [5], Hemici-Olive and Olive [6], Reichert and Schoetter [7], and Fink et al. [8]. 

Acrylonitrile-butadiene copolymers may also be prepared by the use of Ziegler-Natta catalysts. Catalysts such as a triethylaluminium, aluminium chloride and vanadium chloride combination give copolymers with a high degree of alternation. Such copolymers appear to have improved mechanical properties but have not attracted much commercial interest. 

This review is a survey of the applications and properties of supported liquid phase catalysts (SLP). By a supported liquid phase catalyst is meant the distribution of a catalytically active liquid on an inert porous support and the behaviour of such systems raises many interesting questions on catalyst chemistry, mass transfer in catalysts and reactor design. It is noteworthy thou that such systems have been employed in the chemical industry for many decades - indeed for over a century in the Deacon process for obtaining chlorine from hydrogen chloride - and of almost equally respectable antiquity are the vanadium based catalyst systems used for sulfuric acid manufacture but the recognition of SLP catalysts as possessing features of their own is much more recent. 

A typical Ziegler-Natta catalyst might be made from TiCl or TiCl and Al(C2H )3. Vanadium and cobalt chlorides are also used, as is A1(C2H3)2C1. When these substances are mixed in an inert solvent, a crystalline soHd is obtained. Early catalysts consisted of the finely divided soHd alone, but in modern catalysts, it is often supported on Si02 or MgCl2. 

Titanium—Vanadium Mixed Metal Alkoxides. Titanium—vanadium mixed metal alkoxides, VO(OTi(OR)2)2, are prepared by reaction of titanates, eg, TYZOR TBT, with vanadium acetate ia a high boiling hydrocarbon solvent. The by-product butyl acetate is distilled off to yield a product useful as a catalyst for polymeri2iag olefins, dienes, styrenics, vinyl chloride, acrylate esters, and epoxides (159,160). 

Vanadium oxide as catalyst, 174 Vinyl chloride, manufacture of, using catalysts, 238... 

Electronic Grade Silicon (EGS). As the first step in the production of electronic grade silicon (EGS), an impure grade of silicon is pulverized and reacted with anhydrous hydrochloric acid, to yield primarily tricholorosilane, HSiClg. This reaction is carried out in afluidizedbed at approximately 300°C in the presence of a catalyst. At the same time, the impurities in the starter impure silicon reactto form their respective chlorides. These chlorides are liquid at room temperature with the exception of vanadium dichloride and iron dichloride, which are soluble in HSiCl3 at the low concentration prevailing. Purification is accomplished by fractional distillation. 

The effects of various metal oxides and salts which promote ignition of amine-red fuming nitric acid systems were examined. Among soluble catalysts, copperQ oxide, ammonium metavanadate, sodium metavanadate, iron(III) chloride (and potassium hexacyanoferrate(II) with o-toluidine) are most effective. Of the insoluble materials, copper(II) oxide, iron(III) oxide, vanadium(V) oxide, potassium chromate, potassium dichromate, potassium hexacyanoferrate(III) and sodium pentacyanonitrosylferrate(II) were effective. 

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