Structure Evolution and Associated Catalytic Properties of PtSn Bimetallic Nanoparticles

Bimetallic nanoparticles (NPs) often show new catalytic properties that are different from those of the parent metals. Carefully exploring the structures of bimetallic NPs is a prerequisite for understanding the structure‐associated properties. Herein, binary PtSn NPs with tunable composition are prepared in a controllable manner. X‐ray characterizations reveal that their structures evolve from SnO2−x‐patched PtSn alloys to SnO2−x‐patched Pt clusters when more tin is incorporated. An obvious composition‐dependent catalytic performance is observed for the hydrogenation of α,β‐unsaturated aldehydes: the selectivity to unsaturated alcohol increases substantially at high tin content, whereas the reaction rate follows a volcano shape. Furthermore, Pt sites are responsible for hydrogen dissociation, whereas oxygen vacancy (Ovac) sites, provided by SnO2−x, drastically enhance the adsorption of carbonyl group. Bimetallic NPs with a complex structure: Varying the composition of a bimetallic nanoparticle (NP) makes its structure and properties very different. The composition‐dependent structure evolution of PtSn NPs from the SnO2−x‐patched PtSn alloy to the Pt cluster (see figure) is reported along with their catalytic property.