Core/Shell Metal Oxides@MIL-53(Al) Nanoparticles as\nCatalyst for the Selective Hydrogenation of Cinnamaldehyde

Metal\noxides@metal–organic framework (MOFs)-based core/shell\nnanostructures demonstrate promising potential in catalytic hydrogenations.\nHowever, the direct nucleation and growth of MOFs on the topologically\ndiverse surfaces of metal oxides face significant challenges due to\nthe high interfacial energy resulting from topological mismatches.\nHerein, we present a facile <i>in situ</i> growth strategy\nfor directly assembling an MIL-53(Al) layer on the surface of CeO<sub>2</sub> nanospheres at low temperatures by mixing and stirring CeO<sub>2</sub> nanospheres and MIL-53(Al) precursors without requiring sacrificial\ntemplates or additional surface modifications. Moreover, key factors\nsuch as reaction time, temperature, and the types of aluminum salts\nand ligands are systematically explored to comprehensively understand\nthe nucleation behavior of MOFs shells. Notably, when active Pt nanoparticles\nare sandwiched between the CeO<sub>2</sub> core and the MIL-53(Al)\nshell, the MIL-53(Al) effectively stabilizes the Pt nanoparticles\nand enhances the selectivity of hydrocinnamaldehyde in cinnamaldehyde\nhydrogenation. CeO<sub>2</sub>/Pt@MIL-53(Al) achieved more than twice\nthe selectivity for HCAL compared to CeO<sub>2</sub>/Pt and even outperformed\nPt/MIL-53(Al). Undoubtedly, this study provides distinctive insights\ninto the nucleation and growth mechanisms of MOFs on metal oxides,\nexpands the strategies for fabricating metal oxides@MOFs core/shell\nnanostructure, and proposes innovative ideas and possibilities for\nbroadening the application domains of MOFs-based materials.