Effect of preparation method and particle size on LaMnO3 performance in butane oxidation
LaMnO3 with different crystal domain sizes and surface areas were prepared by citrate and sol-gel combustion methods and tested as catalysts for butane total oxidation reaction. The catalysts were characterized by N2 physisorption, XRD and SEM. LaMnO3 with crystal domain sizes in the range of 30–90 nm were detected by XRD characterization when high calcination temperature, at least 500 °C for sol-gel combustion method and 700 °C for citrate method, was required to prepare pure nanocrystalline phase. Although LaMnO3 prepared by these two methods had similar crystal domain sizes, BET surface areas of samples by citrate method were significantly larger than that of samples prepared by combustion method. The difference of surface area lies in the morphology differences between the two series of samples (SEM micrographs) generated by strong sintering of samples prepared by combustion method. The catalytic activity of LaMnO3 in butane total oxidation increased with increasing surface area being higher for materials prepared by citrate method. Thus, citrate method showed significant advantages over combustion method in preparation of perovskite catalysts.
Research highlights► LaMnO3 with 30–90 nm particle sizes are synthesized by two different methods. ► LaMnO3 with different particles sizes are tested as catalysts for butane oxidation. ► Citrate method shows advantages over combustion method.
Journal: Catalysis Communications - Volume 12, Issue 15, 15 September 2011, Pages 1437–1441