LaCoO3 perovskite on ceramic monoliths – Pre and post reaction analyzes of the partial oxidation of methane

Powder LaCoO3 perovskite were synthesized using Pechiniʹs methodology. The γ-Al2O3 was deposited on the commercial cordierite ceramic substrate by washcoating. The perovskite was deposited over the monoliths by dip coating with a 80 g/l LaCoO3 suspension. The LaCoO3/γ-Al2O3/cordierite system was characterized by XRD, SEM, TPR and XPS. Results showed that the crystallite sizes of the perovskite remained unchanged after its deposition. XRD results identified LaCoO3 and cordierite phases, without segregation or formation of other oxides. After reduction, the LaCoO3 perovskite is transformed to metallic cobalt. The dip coating technique was efficient for deposition of the mixed oxide on the monolithic structure, without forming other structures. The adjustment of the zeta potential of the suspension was adequate to prevent agglomeration of the LaCoO3 particles. The catalysts were active for the POM reaction and were extremely stable during the tests. After reaction, RAMAN spectroscopy and SEM images revealed the presence of carbon nanotubes with large amount of defects at the surface.