A simple co-nanocasting method to synthesize high surface area mesoporous LaCoO3 oxides for CO and NO oxidations

Abstract

High surface area mesoporous LaCoO3 oxides (270m2g−1) with well crystallized perovskite framework have been successfully prepared via a simple one-step co-nanocasting method using the mesoporous SiO2 (KIT-6) template. The prepared mesoporous LaCoO3 material shows relatively high catalytic activity for CO oxidation and the complete CO conversion has been achieved at about 190°C, which is about 75°C lower than that of the non-mesoporous LaCoO3. Moreover, compared with non-mesoporous counterpart, the prepared mesoporous LaCoO3 possesses much higher catalytic activity for NO oxidation, showing rather higher NOx storage capacity. The NO removal ratio is high up to 64% under low temperature (310°C). The enhanced catalytic activity of the mesoporous LaCoO3 for CO and NO oxidation is attributed to its high surface area and crystal lattice defects. A catalytic mechanism of CO and NO oxidation was proposed.