Perovskites nanocast

Keywords Perovskites, Nanocasting, Conunercial Carbons, NO reduction, CO... 

Figure 1. XRD patterns of (a) LaFe03 and (d) LaFeo.6Coo.4O3 conventionally perovskites (b) LaFeOo and (e) LaFeo oCoo Oo perovskites nanocasted from Fluka 05120 carbon (c) LaFe03 and (f) LaFeo 6C00.4O3 perovskites nanocasted from Black Pearls 2000 carbon. The capital letters indicate the observed phases as following (L) La203 (O) C03O4 (F) Fe203.

Synthesis and Catalytic Applications of Nanocast Oxide-Type Perovskites... 

Table 3.2 Structural parameters of the nanocast mesoporous perovskites obtained by performing N2 physisorption analysis at -196°C...

Figure 3.3 TEM images of nanocast mesoporous perovskites synthesized using ordered mesoporous KIT-6 siiica as hard tempiate.

The use of oxide-type perovskites as dry reforming catalysts will be dealt with extensively in Volume II of this book. In this chapter, we report one example of such catalyst in order to highlight the potentiahty of the nanocasting preparation method as a way to control bulk and smface properties of perovskite-derived catalysts. 

Initial monitoring of the catalytic activity was performed using as-synthesized perovskites without any reduction step. In the case of conventional LaNiOs, very low values of conversions were observed for both CH4 and CO2 until 800 °C. For nanocast LaNiOs, comparatively higher conversions (approximately 40%) were... 

For many oxides, including mixed metal oxides, of catalytic interest, preparing a high-surface-area solid with thermally stable porous structure was extremely difficult until recentiy. The hard templating procedure provides a systematic solution to this problem. Nanocasting that makes use of a mesostructured solid template is a special case. Both mesostructured silica and mesostructured carbon have been demonstrated so fer as hard templates. Rather precise replicas of these nanomolds have been obtained for a variety of oxide-type perovskites. Unprecedented specific surface areas in the 150-200 m /g were reached. 

Wang, Y., Ren, J., Wang, Y., Zhang, F., Liu, X., Guo, Y., and Lu, G. (2008) Nanocasted synthesis of mesoporous LaCo03 perovskite with extremely high surfece area and excellent activity in methane combustion. /, Phys. Chem. C, 112 (39), 15293-15298. 

Novel oxygen carriers for chemical looping combustion Lai ,Ce ,B03 (B = Co, Mn) perovskites synthesized by reactive grinding and nanocasting. Energy Environ. Scl, 4 (10), 4258-4269. 

F. (2014) Nanocast LaNiOs perovskites as precursors for the preparation of coke-resistant dry reforming catalysts. 

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