NANOSTRUCTURED LANTHANUM MANGANITE PEROVSKITES IN CATALYST APPLICATIONS

作者：Rezlescu N^*; Rezlescu E; Doroftei C; Popa P D; Ignat M

来源：Digest Journal of Nanomaterials and Biostructures, 2013, 8(2): 581-587.

• Perovskite
• Microstructure
• Self-combustion
• Catalyst

Finding less expensive alternatives to noble metals catalysts is vital for implementing catalytic combustion on a wide scale, and lead substituted lanthanum manganites are a promising option. Nanometer particles of La0.6Pb0.4MnO3 and La0.6Pb0.4MnO3 + 0.2MeO (where Me = Mg or Ca) with perovskite structure were prepared by self-combustion method followed by heat treatment at 1000 degrees C in air. The effects of excess divalent ions (Ca2+ and Mg2+) in La0.6Pb0.4MnO3 manganite perovskite on the catalyst properties were investigated. The morphological and surface properties are of great importance in the catalyst activity. Structure, specific surface area and grain size were determined using XRD, nitrogen adsorption (BET) and SEM analysis. X-ray diffraction evidenced the crystallinity and the nanosize of the perovskite crystallites. Following Mg or Ca addition to La0.6Pb0.4MnO3, a decrease in the grain size was detected by SEM. Rather large values for specific surface areas were obtained (of about 8 m(2)/g). The perovskite manganite powders have been tested in the catalytic combustion of three diluted gases: acetone/air, ethanol/air and methanol/air. The experimental results revealed that it was possible to start the catalytic combustion of the gases over the surface of the three perovskite at much lower temperatures than catalyst-free combustion.

• 出版日期2013-6