High temperature conduction and methane conversion capability of BaCeO3 perovskite

作者：Bezerra Lopes Francisco Wendell; Arab Madjid^*; Macedo Heloisa Pimenta; de Souza Carlson Pereira; de Souza Joao Fernandes; Gavarri Jean Raymond

来源：Powder Technology, 2012, 219: 186-192.

DOI：10.1016/j.powtec.2011.12.039

• Ceramics
• Barium cerate
• Catalysis
• Methane conversion
• Electrical impedance spectroscopy
• Electrical transitions

The transport properties and reactivity in gases of a BaCeO3 perovskite phase have been investigated to develop new materials for methane conversion in microsystems. The polycrystalline material has been synthesized at moderate temperature using a specific modified EDTA-citrate complexing methodology. The BaCeO3 phase has been characterized by X-ray diffraction (XRD), thermogravimetry and differential thermal analyses (TG/DTA), scanning and transmission electronic microscopy techniques (SEM. TEM), energy dispersive X-ray (EDX) and surface area analyses. A Rietveld analysis of diffraction profiles has allowed determining the structural parameters of the as prepared material. Next, the catalytic efficiency of the BaCeO3 phase with air-methane gas flows has been characterized by Fourier transformed infrared (FTIR) spectroscopy: the conversion rate of CH4 into CO2 has been determined from the intensities of CO2 absorption bands, as a function of temperature (from 450 to 750 degrees C) and reaction time. Finally, the electrical conduction of compacted BaCeO3 pellets has been determined from electrical impedance spectroscopy analyses between 300 degrees C and 950 degrees C. A series of electrical transitions correlated with well known structural changes has been observed between 300 degrees C and 950 degrees C. The starting catalytic activity of BaCeO3 might be correlated to the enhanced ionic conduction observed above 450 degrees C.

• 出版日期2012-3