화학공학소재연구정보센터
Langmuir, Vol.19, No.24, 10409-10413, 2003
Improved silanization modification of a silica surface and its application to the preparation of a silica-supported polyoxometalate catalyst
A hydrolyzed silane ((C2H5O)(3)Si-(CH2)(3)-NH2) was anchored on the surface of silica nanoparticles, forming silica-immobilized silane. After calcination, the silane-modified silica (M-silica) can attract heteropoly acid (HPA) efficiently. It has been shown that the presence of water in the atmosphere is necessary for the hydrolysis of silane molecules and is also essential for the silanization modification of the silica particles. The efficient silanization modification enabled the high loading ratio of HPA on the surface of the M-silica. The interaction between the NH2 groups in the silanes and the HPA molecules was demonstrated by results of control experiments. The catalytic properties of the M-silica-supported 12-tungstophoshoric acid (HPW) and 12-tungstosilic acid (HSiW) were tested by an oxidation reaction of hydrocarbon (cyclohexane and octane-1) using oxygen as oxidizers. A high conversion of more than 60% was obtained for the HPW/M-silica complex. To our knowledge, it is the highest conversion percentage obtained for the oxidation of cyclohexane.