RT journal article
T1 Influence of the Thermal Processing and Doping on LaMnO3 and La(0.8)A(0.2)MnO(3) (A = Ca, Sr, Ba) Perovskites Prepared by Auto-Combustion for Removal of VOCs
A1 Di Benedetto, Natasha
A1 De los Santos, Carolina
A1 Yeste Siguenza, María del Pilar
A1 Morais, Jonder
A1 Martins Alves, Maria Do Carmo
A1 Amaya, Alejandro
A1 Suescun, Leopoldo
A1 Gatica Casas, José Manuel
A1 Vidal Muñoz, Hilario
A1 Castiglioni, Jorge
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 VOC
K1 perovskites
K1 catalytic oxidation
K1 acetone
K1 auto-combustion synthesis
AB Single-phase oxygen stoichiometric LaMnO3 and doped La(0.8)A(0.2)MnO(3) (A = Ca, Sr, Ba) perovskites have been prepared by a simple one-step auto-combustion method. Cation-deficient LaMnO3+delta and La(0.8)A(0.2)MnO(3+delta) were obtained by calcination of the former samples in air at 750 degrees C. The samples were characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, temperature-programmed reduction, temperature-programmed oxygen desorption, and N-2 physisorption in order to apply them as catalysts in the complete catalytic oxidation of acetone as a model volatile organic compound. The studied phases show the expected orthorhombic and rhombohedral perovskite crystal structures. Catalytic experiments performed with all the samples show measurable activity already at 100 degrees C. At 200 degrees C, doped La(0.8)A(0.2)MnO(3) samples show higher activity than undoped LaMnO3, with increasing conversion with larger A-cation size. Calcined samples also show higher activity than as-prepared ones making La0.8Ba0.2MnO3+delta the best catalyst at this temperature. All doped samples show >95% acetone conversion at T >= 250 degrees C with a weak dependence on the sample processing or A cation doping. The collected evidence confirms that the most important factors for the catalytic activity of these oxides are the Mn4+/Mn3+ molar ratio on the surface of the samples and the cation-deficiency of the bulk perovskite structure. In addition, increasing the symmetry of the bulk crystal structure appears to have an additional favourable effect. Despite the observation of the presence of surface carbonates, we show that it is possible to use the as-prepared samples without further thermal treatment with good results in the oxidation of acetone.
PB MDPI
SN 2073-4344
YR 2022
FD 2022-08
LK http://hdl.handle.net/10498/28072
UL http://hdl.handle.net/10498/28072
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 14-nov-2026