Selective etching of in-situ formed La2O3 particles to prepare porous LaCoO3 perovskite for catalytic combustion of ethyl acetate

Abstract

A selective etching method was reported to prepare porous LaCoO3 perovskite for catalytic combustion of ethyl acetate (EA). The porous LaCoO3 was obtained by selectively etching of in-situ formed La2O3 particles with acetic acid (HAc) from a pre-synthesized LaCoO3-La2O3 composite. XRD, N2 physisorption, ICP-OES, TEM, XPS, H2-TPR and O2-TPO showed that the etching of La2O3 with HAc not only generated surface La defects, but also improved the porosity, the exposure of active sites and the redox properties of the material. Therefore, the porous LaCoO3 can contact and activate the reactants efficiently, accelerating the reaction rate. LCO2.0-30, prepared with La/Co molar ratio of 2.0 and etched for 30 min, was the most active catalyst even in presence of H2O, with 100% EA conversion at 220 °C, due to its abundant porosity, surface active sites and strong reducibility. A possible reaction mechanism for EA combustion conducted on porous LaCoO3 perovskite was proposed.