Abstract
In this study, Cu@SiO2 yolk shell nanoparticles was catalysts applied in methanol reforming reaction. Yolk shell nanoparticles was one kind of nanoreactors. Copper nanoparticles were synthesized through reducing methods and were protected by positive organic surfactants. Silica shell were produced by sol-gel reaction from silica precursors comprising carbon. After calcination, all the carbon were removed and Cu@SiO2 was complete. Cu@SiO2 utilized in partial oxidation of methanol reforming reaction was found that the shell structure avoided the copper nanoparticles form aggregation for cycling uses so that the methanol conversion could maintain at least 40% at 250℃. In contrast, co-precipitation copper silica catalysts were dropped to 10% methanol conversion after cycling uses. Moreover, Cu@SiO2 loading in the micro-channel system had greater hydrogen yield and greater methanol conversions than co-precipitation copper silica nanoparticles with the same copper weight. The reason was that the porous shell were deemed as brunches to support copper core in order not to cover surface of copper by each other. Yolk-shell structure provided nanoparticles with great durability; however, it could also hinder reaction gas to attach to copper. In this study, toluene was chosen to detect the capability to desoption from porous silica shell. DRIFT(diffuse reflectance infrared fourier transform spectroscopy) was utilized to detect the gas departure from the catalysts. For Cu@SiO2, toluene started leaving the porous silica shell at 70℃ and it was considered the silica shell was not an obstacle for reaction gas and products.