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Perovskite/perovskite‐like (LaBO3, B=Mn, Co or Ni)/Co3O4 with different morphologies were successfully integrated onto the surface of three‐dimensional (3‐D) cordierite honeycomb ceramics by two‐step combination method of hydrothermal synthesis and impregnation for the catalytic combustion of o‐xylene. The La2NiO4/Co3O4 composite exhibits a 3D hierarchical hollow microsphere construction assembled by numerous nanowires, which is different from the nanowire structure of LaMnO3.15/Co3O4 and LaCoO3/Co3O4. Compared to LaMnO3.15/cordierite, Co3O4/cordierite, LaMnO3.15/Co3O4/cordierite and LaCoO3/Co3O4/cordierite, the La2NiO4/Co3O4/cordierite catalyst possesses lower light‐off temperature and better catalytic performance. The higher catalytic activity of La2NiO4/Co3O4/cordierite catalyst may be correlated with higher specific surface area, larger oxygen storage and the synergistic effect of the La2NiO4 and Co3O4. In addition, when the perovskite‐like loading was 11.39 wt% and calcined at 600 °C for 4 hours, it exhibited the best catalytic performance for o‐xylene oxidation with 90% conversion at 299 °C. In addition, the catalyst also has good conversion stability.

Employing First-principles calculations, we have studied the electronic structure and polarization properties of the fluoroperovskite NaMgF3/NaCaF3 superlattices. The in-plane lattice constants of the superlattices are found to lie between those of the bulks. The Berry phase calculations show that the polarization of the NaCaF3 bulk is much larger than that of the NaMgF3, and the polarization of the NaMgF3/NaCaF3 superlattices can be tuned by altering the stacking periodicity. The band structure dependence of the stacking period is also investigated.

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