Catalytic activity for methane combustion of the perovskite-type La1−xSrxCoO3−δ oxide prepared by the urea decomposition method

Abstract

Four methods were adopted to prepare perovskite-type oxide with molar ratio of La/Sr/Co=0.9/0.1/1.0. The oxide prepared by the urea decomposition method showed the highest catalytic activity for methane combustion and a good durability at 600°C for 90h. Surface structure features of this oxide were discussed by use of XPS data. This method was further applied to prepare other perovskite oxides with nominal degree of substitution x=0.0, 0.2 and 0.3. Relation of catalytic activity with degree of substitution was discussed in view of cooperation of surface lattice oxygen vacancy with surrounding cobalt ions at lower oxidation states.