Double shelled hollow nanospheres with dual noble metal nanoparticle encapsulation for enhanced catalytic application.

We report the design and realization of double shelled @CeO2/M@M/TiO2 (M = Au and/or Pd) nanospheres with dual noble metal nanoparticles encapsulated in metal oxide shells via a layer-by-layer deposition process followed by an alkali etching method. The resulting nanospheres possess uniform sizes, variable shell components and thicknesses, adjustable noble metal nanoparticles encapsulated, regulable chamber spaces between the two shells, and good structural stability, which can be used as unique microreactors with extremely high catalytic activity and stability in the Suzuki-Miyaura coupling reaction, benzyl aerobic alcohol oxidation, and 4-nitrophenol reduction reaction due to their structural features with multiple interactions and strong synergistic effects between the noble metal nanoparticles and metal oxide shells, and less depletion of catalytic active species. The designed double shelled hollow @CeO2/M@M/TiO2 nanocatalysts can be used as novel catalyst systems with highly efficient catalytic performance for various catalytic reactions depending on their shell components and noble metal nanoparticles encapsulated. The synthetic strategy provides a new methodology to design high-performance and multifunctional nanocatalysts.