Nanocomposites of Platinum/Metal–Organic Frameworks Coated with Metal–Organic Frameworks with Remarkably Enhanced Chemoselectivity for Cinnamaldehyde Hydrogenation

Abstract The encapsulation of metal nanoparticles (MNPs) within metal–organic frameworks (MOFs) to form core–shell structural nanocomposites is one of the most promising methods to enhance the durability and selectivity of MOF‐supported metal catalysts. However, it is still a challenge to fully encapsulate tiny MNPs inside MOFs. Herein, we report a facile and general strategy to coat MOFs on the surface of Pt/MOFs by direct homoepitaxial growth. The obtained Pt/MOFs@MOFs nanocomposites retained the intrinsic properties (e.g., crystalline structure, pore texture, and surface area) of Pt/MOFs. Strikingly, the MOF‐coated materials exhibited a significantly enhanced chemoselectivity compared to the uncoated materials, for example, in the hydrogenation of cinnamaldehyde, the selectivity to cinnamyl alcohol through C=O hydrogenation was improved from 55 to 96 % at complete conversions of cinnamaldehyde. Moreover, Pt/MOFs@MOFs can be recycled without any remarkable loss in both activity and selectivity. The enhanced catalytic selectivity and stability of MNPs/MOFs could be related to the synergetic effects of the electron donation and nanoconfinement offered by the surrounding MOF networks.