Gold Nanoparticles Intercalated into the Walls of Mesoporous Silica as a Versatile Redox Catalyst

A nanoscaled reactor framework of well-dispersed gold particles intercalated into the walls of mesoporous silica (GMS) was prepared by functionalizing silica with thioether groups. The GMS maintains mesoporous structure with uniform pores of 5.6 nm and possesses high surface area of more than 800 m(2).g(-1). Very recently, we reported that the GMS catalyst was very active for the oxidation of alkanes and alcohols but was also durable and recyclable. Here, we show that the catalyst is also very active for the reduction of p-nitrophenol (PNP) and methylene blue (MB) displaying catalytic activity in the reduction of PNP with Knor-PNP of 45.9 mmol(-1).s(-1). The unobstructed ordered mesoporous structure of the GMS catalyst and the small size of gold nanoparticles are the main factors leading to high catalytic activities. Further, for reduction of MB, the catalytic rate of the catalyst decreases by less than 6% when recycled 10 times. Therefore, the nanoreactor framework catalyst is very robust and is readily separable and reusable, demonstrating attractive potential for practical applications.