ISSN:
1608-3210
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The possibility for the formation of garnet structures in the Mn–Fe–Zr–O and Ca–Sm–Zr–O systems obtained by the precipitation of the corresponding salts is studied. It is shown that, in the Mn–Fe–Zr–O system, garnet is crystallized at 860–920°C, for which probable cation distribution is estimated to be {Zr2.5 4+Mn0.5 2+}[Mn2 2+](Fe2.5 3+Mn0.5 3+)O12. In the Ca–Sm–Zr–O system, the perovskite CaZrO3, pyrochlore Sm2Zr2O7, and CaO are formed at 900–1200°C, but compounds with garnet structures are not found. The reported systems are characterized by surface areas of 300–450 m2/g at ≤450°C, and they have the polydisperse distribution of pores over sizes. The introduction of surfactants at the stage of component mixing enables an increase in the overall pore volume and mechanical strength of these systems. The Mn–Fe–Zr and Ca–Sm–Zr compositions are active catalysts for the complete oxidation of hydrocarbons.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1026685422492
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