Ammonium paramolybdate

Catalysts were normally prepared by double impregnation of the alumina support, first with ammonium paramolybdate solution to give 12 wt% MoO (8% Mo) after 500°C calcination, then with cobalt... 

Acidification of the leach liquor with sulfuric acid produces solutions containing Mog0264-, which is extracted into a solution of tertiary amine hydrogen sulfate as described previously. Loaded organic phases are stripped with aqueous ammonia to give solutions from which ammonium paramolybdate can subsequently be crystallized ... 

Calcination of the ammonium paramolybdate yields molybdenum(VI) oxide of high purity 208... 

In the Mo/Al catalyst, the precursor is normally ammonium paramolybdate, which has the formula (NH4)6Mo7024. The Mo... 

Figure 8 Acidic and basic impregnation of Al2 03 with ammonium paramolybdate...

The 6-heteropoly compounds of molybdenum have been studied extensively and are well understood. Typical examples are the 6-molybdotellurate anion, [TeMo6024]-6, and the 6-molybdochromate(III) anion, [CrMo6024H6]-3. These are usually prepared by the reaction of ammonium paramolybdate with a soluble salt of the central atom7. Some of these are stable only in very mild acid solution and caution should thus be exercised in preparing them. 

Similarly numerous complex salts are derived from tungsten such as the para- and meta-tungstates, the structures of which are, however, not yet completely elucidated. They are associated with the heteropolyacids, for example, (NH4)6 [Mo(Mo04)6].4H20, ammonium paramolybdate. 

Steps 2 and 3 contain empirical representations of the x-ray amorphous HTO material. Co, Mo, Pd, and NiMo HTO catalysts are prepared by similar procedures. Co, Ni, and Pd were exchanged using metal nitrates Mo was added by ammonium paramolybdate. HTO-Si support materials were made by adding tetraethyl orthosilicate to the tetraisopropyl titanate prior to addition of... 

SYNS AMMONIUM PARAMOLYBDATE DIA.MMONIUM MOLYBDATE MOLYBDIC ACID DIAxMMONIUM S.M.T... 

NITROSOPHENYLHYDROXYLAMINE see AN0500 AMMONIUM OXALATE see ANO750 AMMONIUM PARAMOLYBDATE see ANM750 AMMONIUM PENTADECAFLUOROOCTANATE see ANP625... 

For the synthesis of Mo/V/Te/Nb/O catalysts, ammonium paramolybdate, vanadyl sulfate, ammonium niobium oxalate and tellurium oxide or telluric acid are mixed as aqueous solutions or slurries and dried at about 150°C. These mixed slurries are then calcined at 500-650°C in a N2 stream [39]. In addition to the dominant Ml and M2 phases, impurity phases, for example M0O3, Mo,5V9O40 and Mo3Nb20ii, are also observed [28c]. It should be noted that Mo-V-Te-O catalysts cannot be obtained by the dry-up method. 

Condensation formulaj have also been suggested." For example, ammonium paramolybdate, which has been obtained in the crystalline form in the anhydrous state, may be expressed by the formula... 

When increasing quantities of hydrochloric acid are added to a saturated solution of ammonium paramolybdate, a series of hexabasic polymolybdates, having the general formula ... 

Under certain conditions bismuth may be quantitative precipitated from a weak nitric acid solution by means of excess of ammonium paramolybdate, in the form of bismuth ammonium molvbdate, Bi(NHJ(Mo04)a. ... 

Indium Molybdate, In2(Mo04)3.2H20, is obtained as a white voluminous mass when ammonium paramolybdate solution is added to solutions of indium salts. 

From a solution containing ammonium paramolybdate (1 molecule) and magnesium nitrate (2 molecules) colourless ciystals have been obtained. which may be formulated - (XH4)3.Mg.Hj[H2(Mo04)u].6H20. 

A complex salt, of composition (NH4)g[Sn(Mo2O7)6].20H2O, is obtained as a microcrystalline white powder by the action of ammonium paramolybdate on ammonium chlorostannate. 

A 12.5% M0O3/AI2O3 catalyst was prepared by using a mixture of -alumina and ammonium paramolybdate, and calcined in air at 823 K for 3 h (Nikki Chemicals Co.). Nitriding of the... 

Unless otherwise noted, catalysts were prepared by coprecipitating the hydrous oxides of uranium, antimony, and a tetravalent metal from a hydrocholoric acid solution of their salts by the addition of ammonium hydroxide. The precipitates were washed, oven dried, then calcined at 910 C overnight or at 930 C for two hours to form crystalline phases. Attrition resistant catalysts, containing 50% by weight silica binder, were prepared by slurrying the washed precipitate with silica-sol prior to drying. In some cases, small amounts of molybdenum or vanadium were added by impregnating the oven dried material with ammonium paramolybdate or ammonium metavanadate solution. The details of these preparations may be found elsewhere (5-8). 

Tetramolybdates or metamolybdates, M20-4Mo03- H20, are formed from concentrated solutions of alkali molybdates treated with 1.5 mols per mol of hydrochloric acid. Octamolybdates are obtained similarly from solutions containing 1.75 mols per mol of hydrochloric acid or by adding the calculated amount of M0O3 to ammonium paramolybdate solution. Both the tetra- and octa-molybdates are derived from the ion [Mo8026]4. ... 

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