Lanthanum ferrite perovskites

Ammonia oxidation for the manufacture of NO (an intermediate in nitric acid production) is carried out in an oxidation reactor incorporating a Ca- and Sr-substituted lanthanum ferrite perovskite membrane. NO selectivity of the order of 98% is achieved by the membrane, while N2 is rejected completely. The membrane reactor obviates the need for expensive noble metal catalysts and does not produce environmentally harmful N2O. 

Single-phase perovskite MIECs such as Sr-doped lanthanum cobaltite (LSC), lanthanum ferrite (LSF), lanthanum cobalt ferrite (LSCF) and samarium cobaltite (SSC), and Ca-doped lanthanum ferrite (LCF) [13] are sometimes used alone in SOFC cathodes, as depicted in the lower right-hand comer of Figure 6.1, but combining an... 

Nowadays lanthanum ferrites and chromiiun doped lantlianide aluminates with perovskite structure are used as ceramic pigments because they have colorimetric properties, high thermal stability, line particle size and chemical resistance. Also, the ferrites have interesting magnetic properties and the aluminates are materials having photoluminescence properties. 

Oxygen Tracer Diffusion Coefficient (D ), Oxygen Surface Exchange Coefficient (Ar) and Oxygen Ionic Conductivity (a, in air) of Doped Lanthanum Cobalt Ferrite-Based Perovskites... 

The MS signals of NO (m/e=30) and O2 (m/e=32) as functions of desorption temperature were recorded during NO-TPD imder He flow for perovskites (Table 6). A broad NO desorption centered at 200 °C with one minor shoulder at 90 °C and another one at 388 °C was observed in the TPD of NO profdes for LaCoOs. Upon Cu substitution the low temperature peak is entirely suppressed, the 200 °C one is substantially increased and shifted to higher temperature so that it interferes with the minor high temperature one. Similar NO desorption features were found for lanthanum manganites and ferrites after NO adsorption, representing three superimposed desorption peaks. In Section 4, TPD of NO + O2 studies over... 

A lanthanum calcium ferrite (LCF) perovskite system (LaxCai-xFeOs) was joined to itself to demonstrate the feasibility of the TLP method. LCFs can be used as a component of air separation membranes, so the assemblies need to operate at high temperatures. Therefore the joint interface needs to resist creep, avoid problems with thermal cycling, and be chemically stable in the high-temperature environment. Ideally, the interface in such systems is the same as the parts in the assembly. 

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