Influence of preparation method on performance of a metal supported perovskite catalyst for combustion of methane

Abstract

A different method was employed for the preparation of a metal supported perovskite catalyst for the catalytic combustion of methane. The prepared metallic catalysts were characterized by means of X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and also by ultrasonic and thermal shock tests and catalytic activity. It was found that the process factors during the preparation, e.g. the preparation of the catalyst precursor and the coating slurry, the calcination temperature, all had strong effects on the activity and stability of the coated catalyst. Based on the experimental results, it was proposed that the sample adopted spray-pyrolysis method showed better catalytic activity and adhesion stability than those adopted co-precipitation and sol-gel. The increasing calcinations temperature could enhance adhesion stability, but reduce catalytic activity. For the coated samples, XRD illuminated that the typical well-crystallized perovskite structure was formed on the metallic surface after calcined at 800 °C. SEM and TEM micrographs of the samples showed obvious dissimilarity at morphology aspect by different preparation methods. The LaMnO 3 catalyst on the support by the spray-pyrolysis method had a mass loss 26% after 30 min ultrasonic treatment and 7% after 10 times thermal shock.