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

High surface area mesoporous LaCoO₃ oxides (270 m² g^-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 LaCoO ₃ 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 NO_x 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.