(582bx) Aqueous One-Pot Synthesis of Pd-Based Core@Shell Catalysts with Tunable Core and Shell Sizes
Here, we are reporting a versatile, water-based and therefore environmentally benign synthesis method to facilitate the use of core@shell catalysts. The described method can be used to prepare core@shell nanoparticles with Pd cores and oxide shells (e.g., SiO2, CeO2) with independently tunable core and shell sizes. By using water as the synthesis medium, the new method effectively overcomes the limitations of previously reported synthetic approaches that require the use of toxic organic solvents. In addition, not only the sizes of the cores and the shell, but also the compositions of the resultant core@shell nanoparticles could be adjusted by making simple modifications to the synthesis procedure. The prepared catalysts were characterized by transmission electron microscopy, X-ray diffraction, and nitrogen-physisorption to confirm the morphology with different compositions. Following the characterization, the accessibility and the catalytic activity of the core was tested using simple probe reactions such as the oxidation of CO. Some of these novel core@shelll structures exhibited remarkable thermal stability, maintaining the particle size and pore structure at very high temperatures (800-900 °C), close to those one may encounter in automotive exhaust applications.