The shape evolution from PtxCoy@Co cubes to PtxCoy multicubes for selective hydrogenation of α,β-unsaturated aldehyde.

We report the synthesis of PtxCoy@Co cubes and PtxCoy multicubes through use of the previous structure as a seed precursor to induce the formation of the latter. Herein, PtxCoy nanocrystals underwent a shape evolution from a core-shell structure to multicubes under an identical synthetic condition via using the previous structure serving as a seed precursor to induce the formation of the latter. PtxCoy@Co cubes can be viewed as a PtxCoy octapod core coated by a Co atom shell that exhibits complete selectivity towards the C=C bond of unsaturated aldehydes. The Co shell of PtxCoy@Co was further substituted by introducing Pt atoms, followed by successive deposition of Pt on PtxCoy, and interdiffusion between Pt and Co, leading to formation of multicubes. Such multicubes gave rise to superior catalytic activity with higher selectivity for the C=O bond of unsaturated aldehydes compared to pure Pt nanocubes and a commercial Pt/C catalyst.