Enhanced Catalytic Reduction of 4-Nitrophenol over Porous Silica Nanospheres Encapsulating Pt-SnxOy Hybrid Nanoparticles

In this article, Pt-SnxOyhybrid nanoparticles encaged in porous silica nanospheres (Pt-SnxOy@PSNs) were prepared by using 1-dodecanethiol (C12-SH) as a coordination agent to confine Pt and Sn ions in a microemulsion system, which is formed by cetyltrimethylammonium bromide (CTAB) and C12-SH as co-surfactants in water. Compared with Pt@PSNs, when different molar ratios of SnxOywere introduced into Pt@PSNs to form Pt-SnxOy@PSNs, the catalytic efficiency of 4-nitrophenol (4-NP) reduction with NaBH4can be significantly enhanced. At molar ratios of 4-NP/Pt of 150/1, the 4-NP conversion reached 100% over Pt-SnxOy@PSNs with Pt/Sn molar ratios of 1/0.75 in 8 min. This catalytic performance showed a slight decrease after six reaction cycles. This enhanced catalytic efficiency can be ascribed to the synergistic effect between Pt and SnxOy,and the protection of porous silica nanostructures can effectively improve the stability of the catalyst.