Shape-controlled synthesis of Au–Pd bimetallic nanocrystals for catalytic applications
Au–Pd nanostructured materials have been recognized as important heterogeneous catalysts in various reactions, due to their superior activities caused by the ensemble and ligand effects. In recent years, shape-controlled synthesis of noble metal nanocrystals (NCs) provided a brand-new insight for improving the performance of catalysts. The electronic properties and catalytic activities of Au–Pd NCs could be optimized by tuning their shape and composition engineering. This review describes recent progress in the design and synthesis of shape-controlled Au–Pd bimetallic NCs and their emerging catalytic applications. The review starts with a general discussion of various applications of Au–Pd catalysts and the significance of preparing shape-controlled Au–Pd NCs, followed by an overview of synthetic strategies for two different structures of Au–Pd bimetallic catalysts: a core–shell structure and an alloy structure. We also put forward the key factors for the preparation of Au–Pd core–shell and alloy structures. Additionally, we discussed the unique optical properties and structural effects of shape-controlled Au–Pd NCs. These recent advancements in the methodology development of Au–Pd bimetallic NCs offer numerous insights for generating Au–Pd NCs with a number of unique geometries in the future. Furthermore, the systematic synthesis of core–shell or alloy structures would provide insights for the preparation of other bimetallic NCs.