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.