Manganese pyrophosphate

The structure of the active component, manganese pyrophosphate, has been reported in the literature (24). It is layer like with planes of octahedrally coordinated Hn ions being separated by planes of pyrophosphate anions (P20y ). Examination of models of this compound gave calculated Hn-Hn thru space distances of 3.26 and 3.45 angstroms, a metal-metal distance close to that found for binuclear dibridged peroxo- and superoxo- complexes of cobalt ( ). 

Analogous methanol adsorption/desorption experiments conducted with the supported manganese pyrophosphate catalyst gave the following results 1) A single desorption peak centered at lOO C is observed (Figure 8). 2) Mass spectral analysis indicates the... 

Figure 8. Temperature Programmed Desorption of methanol from the ferric molybdate (dashed line) and the manganese pyrophosphate (solid line) catalysts determined gravimetrically.

Figure 11. Mechanistic proposal for the aamoxidation of methanol to HCN over the ferric molybdate and the manganese pyrophosphate catalysts.

CAS 10101-66-3 EINECS/ELINCS 233-257-4 Synonyms Ammonium manganese pyrophosphate Cl 77742 Diphosphoric acid, ammonium manganese (3+) salt (1 1 1) Manganese ammonium pyrophosphate Pigment violet 16 Classification Inorganic salt Empirical H4O7P2 H N Mn Toxicology TSCA listed... 

The effect of acetonitrile on the kinetics of oxidation of ascorbic acid by Cu(II) and the ferrocenium ion in aqueous acetonitrile has been studied, as has the similar oxidation using the Cu(II)-tyrosine complex, for which a mechanism has been proposed. A reinvestigation of the oxidation of ascorbic acid by Fe(III) has shown catalysis by even small amounts of added chloride, 7 and the kinetics and mechanism of the oxidation of ascorbate by manganese pyrophosphate have been studied. The heat stability of aqueous solutions of ascorbic acid is increased witli reduced o gen concentrations, with Cu(II) and Fe(II) accelerating decomposition. ... 

Though V-P-0 catalysts are nonselective for ODH of propane, vanadium aluminophosphate (VAPO) catalysts displayed higher propene selectivity, especially for samples with low vanadium content. Moreover, ALPO-5 has an initial selectivity of about 100%, which is associated to the specific stmcture that promotes the accessibility of propane to the dehydrogenation sites, thus contributing to the high selectivity of VAPO catalysts [63]. The vanadium species in the framework of the ALPO-5 was considered as more selective than the polymeric V species. As for their total activity, it appears to be associated with the presence of the vanadium species. Other phosphate containing catalysts have also been tested, such as the manganese pyrophosphate, which shows a propene yield of 16% at 823 K [64]. 

Zhou H, Upreti S et al (2011) Iron and manganese pyrophosphates as cathodes for lithium-ion battraies. Chem Matra- 23 293-300... 

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