Perovskite oxides have been widely confirmed as a promising alternative to precious metals as catalysts for a wide range of environmental protection, energy storage, and conversion devices for their prominent intrinsic electrocatalytic activity, flexible structure, low cost, and easy synthesis. Since its discovery in 1839, perovskite oxide has been the subject of a considerable amount of systematic research in several exploring aspects (e. g., materials synthesis, component regulation, and catalytic properties). The above‐mentioned findings have been extensively reviewed and consolidated in numerous publications. The heterogeneous catalytic performance of perovskite oxides has been significantly affected by their surface composition, electronic structure, and defect chemistry. This study places a focus on the crystal structure and structure regulation of ordered perovskite oxides. Moreover, the recent research progress in areas (e. g., perovskite surface element segregation, law of exsolution, and the mechanism of exsolution) is systematically reviewed. Furthermore, this study highlights potential future directions for the development of perovskite oxides.

A high‐quality joint of the parent metal Al‐25Si‐4Mg‐1Cu alloy (AlSi alloy) was brazed to itself using Zn layer as a filler material. The typical microstructure of AlSi/Zn/AlSi joint was Al‐Zn solid solution, primary Si phase and α‐Al phase. When brazing temperature was increased from 400 to 405°C, Zn began to melt and reacted with Al diffused from base material, then Si phase formed. While the increase in brazing temperature to 415°C caused the gradual buring of Zn from Al‐Zn solid solution, and α‐Al remained. Furthermore, the shear strength of the joint increased because of α‐Al phase and Si phase formation. In addition, with brazing time extending from 8 to 12 min, the amount of Al‐Zn solid solution decreased, while the amount of Si phase and α‐Al phase increased, thus the shear strength of the joint was improved. While the increase in holding time extending to 14 min caused many micro‐voids formed, and the shear strength of the joint was reduced. Finally, the shear strength of the joint brazed at 415°C for 12 min reached 65.6 MPa.