Pt–Co Separation for Enhancing Bimetallic Catalysis in Selective Hydrogenation Reaction

The respective role of each metal or active site is largely unexplored in bimetallic catalysts, since one metal is easily hindered or even covered by another metal. Separating the different metals by a nanoscale distance in the bimetallic catalysts can provide an opportunity to reveal their respective roles and study the synergistic mechanism. Herein, we report a yolk–shell catalyst with a Pt core and a Co shell through atomic layer deposition. Meanwhile, 1-pentanethiol is used as an isolating layer to separate the Pt core and the Co shell. In addition, the thickness is as small as 0.5 nm. In the selective hydrogenation of the cinnamaldehyde reaction, the Pt core is the active site for the decomposition of hydrogen to active hydrogen. Then the active hydrogen can spill over from the Pt surface to the Co shell for hydrogenation of the adsorbed C═O bonds. Meanwhile, the void space provides a confined space for the accumulation of active hydrogen and then further enhances the catalytic performance. Our study opens up an alternative thoroughfare to design efficient bimetallic catalysts.