Molybdenum phosphate

The [Co(en)3]3+ ion has been shown to be a useful template for the synthesis of unusual cobalt, aluminum, gallium, and magnesium phosphates exhibiting framework,632-637 layered638-641 and chain642 structures, as well as for the hydrothermal synthesis of novel zeolites643,644 and other framework structures such as molybdenum phosphates.645... 

Zinc molybdenum phosphate Actirox 102, -106 (Colores Hispania, Spain) Moly-White ZNP, -MZA (The Sherwin-Williams Company, USA) Heucophos ZMP (Dr. H. Heubach, Germany). 

The specific measurement of inhibitor treatment reserves, usually by testing for a particular chemical component, such as zinc, molybdenum, phosphate, or phosphonate. 

Characteristic Unit Zinc aiuminum molybdenum phosphate Zinc calcium strontium aluminum phosphate silicate... 

Veleva, L., Chin, J., and del Amo, B., Corrosion electrochemical behavior of epoxy anticorrosive paints based on zinc molybdenum phosphate and zinc oxide, Progr. Org.Coat., 36, 211, 1999. 

After extraction, in the filtered extract, phosphorus is estimated colorimetrically by adding ammonium molybdate and thereafter reducing the molybdenum-phosphate complex in acidic medium with a reducing agent for which stannous chloride is used. The intensity of the blue colour molybdenum blue is directly related to the quantity of orthophosphate ion and thus provides a measure for the concentration of P in test solution. The absorbance or transmittance is measured spectrophotometrically at 660 mp,. wavelength. 

There seems to be no literature about the direct oxidation of ethane to acetic acid over heteropolycompounds catalysts. Nevertheless, there is a limited amount of literature[10,26-28] about direct oxidation of ethane to acetic acid over oxide catalysts at low temperature (200-350 C). It seems that vanadium and molybdenum are necessary to those catalysts, and the addition of water is useful to increase the production of acetic acid. Roy et al. [10] has proved that vanadium and molybdenum phosphates supported on Ti02-anatase were effective in the direct oxidation of ethane to acetic acid. Considering previous research results, it is suggested that other promoters, such as trcmsition-metal oxides, are necessary to enhance the catalytic activity of the activated H3PMol2O40(Py) in the direct oxidation of ethane to acetic acid. 

High selectivity was also reported for the ammoxidation of 4-methylpyridine, e. g. over vanadium-molybdenum oxides [90] highly dispersed vanadia on sili-cated alumina [91] or on vanadium-containing molecular sieves (VSAPO, VAPO [92], also used for the ammoxidation of 3-methylpyridine [93,94]). The ammoxidation of 2-methylpyridine leads to the formation of large amounts of pyridine, by total oxidation of the methyl group and subsequent decarboxylation, in addition to the desired nitrile [95]. Yields in excess of 90% can, nevertheless, be achieved, e. g. over vanadium-tin oxide at ca 670 K [23] or over molybdenum phosphates [96]. When the ammoxidation of 2-, 3- and 4-methylpyridine over vanadium phosphates was compared catalyst activity and the nitrile selectivity reflected the reactivity order 4- > 3- > 2-methylpyridine, probably as a result of different sterie hindranee [41]. 

Haushaulter, R.C. Mundi, L.A., Reduced Molybdenum Phosphates - Octahedral Tetrahedral Framework... 

Haushalter and coworkers [18-20] have prepared a number of porous molybdenum phosphates using amine templates under hydrothermal conditions. These frameworks have both octahedral molybdenum and tetrahedral phosphate groups. Very recently, a new framework structure was simultaneously prepared by Haushalter [19] and by Peascoe and Clearfield [21]. The framework composition is [Mo202(P04)2H2P04] and is related to the M0OPO4 [22] and (V0S04)2-H2S04 [23] structure types. This framework is very flexible towards the size and shape of the occluded cation when prepared without a template. However, small templates, such as methylamine and di-methylamine have also been used in its preparation. Removal of the amine allows other small molecules to be sorbed [24]. 

Chem. Descrip. Basic zinc molybdenum phosphate hydrate Chem. Analysis 55% Zn, 38.5% PO4,1.7% M0O3 Uses Corrosion inhibitor, pigment for water-based primers (e.g., styrene-acrylic dispersions)... 

The closed-shell nature of aluminosilicates renders them ineffective for certain reactions favoured by transition (d-block) elements. Haushalter has made efforts to prepare stable shape-selective microporous solids involving molybdenum phosphates [15]. These solids are prepared hydrothermally in aqueous HjPO in the presence of cationic templates along with anionic octahedral-tetrahedral frameworks containing Mo in oxidation state less than 5+ and possessing Mo-Mo bonds. Some of these contain around 40 vol% accessible internal void space. There is rich chemistry in these systems and there is considerable potential for applications. Based on this approach one may indeed discover novel microporous and catalytic oxide systems. Several open-framework metal phosphates [16] and carboxylates [17] with different connectivities have been prepared by hydrothermal synthesis. 

However, a certain fraction of the active material reacts with the surface phosphate groups of the support to inactive iron phosphate and molybdenum phosphate. The amount of metal phosphate depends on the specific surface area of the support and the surface concentration of phosphate groups. Both are influenced by the pH of precipitation of the support and by the Al/P ratio in the initial Al3+ and P04 solution. Although the formation of metal phosphate decreases the capacity of the absorbent towards the removal of H2S, the strong interaction with the support ensures a high thermal stability. 

Fig. 6. The supercube of this molybdenum phosphate CS3M04P3O16 is formed by four M04O4 cubes forming the edges of the cell. Striped circles represent Cs-atoms, oxygen atoms are omitted for clarity...

Fig. 7. a Characteristic for the molybdenum phosphate Cs(H30)[Mo202(P04)2(HP04)] is its sheetdike structure where phosphate groups connect the layers, b Water sorption isotherm for the structure shown in a shows an internal void volume of approximately 9%. Squares adsorption branch, circles desorption branch... 

Basic zinc molybdenum phosphate hydrate. Zinc molybdate is added to basic zinc phosphate hydrate so it can be used with water-soluble systems. 

Zinc-based phosphates examples include zinc phosphate, aluminum zinc phosphate, zinc molybdenum phosphate, aluminum-zinc hydroxyphosphate, zinc hydroxymolybdate phosphate, basic zinc phosphate, zinc silicophosphate and zinc aluminum polyphosphate. 

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