H2 generation using Pt nanoparticles encapsulated in Fe3O4@SiO2@TiO2 multishell particles

Metal nanoparticles contained in core-shell nanostructures have emerged as well-defined heterogeneous catalysts. Such particles with a magnetite-supported core could also be easily separated in liquid phase reactions. Herein, we report a synthetic encapsulating method for N nanoparticles on magnetic multishell particles for use as a magnetically separable, thermally stable, and easily recyclable catalyst in liquid phase reactions. Fe3O4@ SiO2-Pt@TiO2 catalysts exhibited high catalytic activity and stability during recycling in H-2 generation tests using the NaBH4 solution. While the Fe3O4 @SiO2-N catalyst without a TiO2 outer-layer not only exhibited high catalytic activity, but also exhibited very unstable performance during recycling tests due to the detachment of N nanoparticles from core-shell particles. Therefore, a thin TiO2 layer at the outer shell of the Fe3O4 @SiO2Pt@TiO2 catalysts was found to enhance the catalytic stability and recyclability for multiple reaction runs.