A novel hierarchical TiO2@Pt@mSiO2 hollow nanocatalyst with enhanced thermal stability

Abstract

A novel hierarchical TiO2@Pt@mSiO2 hollow nanocatalyst with enhanced thermal stability has been synthesized successfully. The formation procedure involves a facile synthesis of SiO2@TiO2@Pt nanospheres and a subsequent solvothermal process. During the hydrothermal process, original TiO2 layer was transformed into a hierarchical nanostructure and, meanwhile, etch-released silica species redeposited on the surface of the in-situ grown TiO2 nanoplatelets. In the catalytic system, the in-situ grown TiO2 nanoplatelets were buried in the redeposited mSiO2 layers and the Pt NPs dispersed uniformly between TiO2 nanoplatelets and mSiO2 layers. Importantly, the redeposited mSiO2 layer provides a physical barrier to prevent Pt NPs from sintering up to 550 °C and the hierarchical TiO2 nanostructure shows an obvious co-catalysis effect in the reduction of 4-NP. Besides, the mSiO2 layer could also control the rapid crystallization process of TiO2 nanoplatelets effectively. In the high temperature reaction of propane dehydrogenation, HHN exhibits a lower deactivation parameter, indicating the excellent thermal stability.