Porous Silica Nanoreactors Encapsulating Pd-SnO<sub><i>x</i></sub> Hybrid Nanostructures for the Catalytic Reduction of 4-Nitrophenol
Kaijie Li, Qin Wang, Qifan Zhao, Hongbo Yu, Hongfeng Yin
Abstract
The synergy between noble metals and metal oxides can effectively improve the catalytic hydrogenation performance. However, precisely controlling the metal–metal oxide interaction remains a significant challenge. In this study, well-defined Pd-SnO x hybrid nanostructures encapsulated in porous silica nanoreactors (Pd-SnO x @pSiO 2 ) were prepared using a microemulsion system comprising water, cetyltrimethylammonium bromide (CTAB), and 1-dodecanethiol (C 12 –SH). Within the system, CTAB and C 12 –SH acted as co-surfactants, forming self-assembled micelles, with Pd and Sn ions coordinated to C 12 –SH. Compared with individual Pd@pSiO 2, Pd 1 -(SnO x ) 0.75 @pSiO 2 exhibited significant improvements in catalytic efficient and stability (6 cycles, conversion >99, and 100% selectivity) for the catalytic reduction of 4-nitrophenol. This improvement is ascribed to the synergy between Pd and SnO x, along with the confinement effect provided by the porous silica shells. This research provides a strategy for constructing reactive and stable noble-metal-based catalysts for the hydrogenation of substituted nitroaromatics.