Temperature dependent electrical properties and catalytic activities of La2O3-CO2*H2O Phase System

Abstract

We present a study of electrical properties and catalytic activities of materials belonging to the hydrated carbonated system La2O 3-CO2-H2O. The polycrystalline hydroxycarbonate, dioxycarbonate, and oxide are prepared via a coprecipitation route followed by heat treatment. The electrical conduction of the phases obtained by thermal decomposition from LaOHCO3, H2O is analyzed by electrical impedance spectroscopy, from 25 C to 950 C, under air. The catalytic properties of LaOHCO3, La2O 2CO3 and La2O3 polycrystalline phases are studied by FTIR spectroscopy, in presence of gas mixtures CO-air and CH 4 -air, at temperatures ranging between 100 C to 525 C. The three materials behave differently in presence of CO or CH 4 gases. © 2009 2009 Bahcine Bakiz et al.