Thesis (M.Eng.)--Chulalongkorn University, 2009

This research focused on in vestigation of characteristics and properties of two types of silica i) spherical silica ii) MCM41 with and without impregnation of titania by hydrolysis of titanium isopropoxide. It was found that The TiO[subscript 2]-MCM microparticle composites (TiMCM) had better thermal stability than The TiO[subscript 2]- spherical silica microparticle composites (TiSSP). Moreover, the titania distribution on the silica surface was good. Furthermore, the investigation in the characteristics of cobalt and nickel supported on the both of silica and TiO[subscript 2]-SiO[subscript 2] microparticle composites. It was found that the reducibilities of cobalt and nickel supported on TiO[subscript 2]-SiO[subscript 2] microparticle composites catalysts were increasing. In addition, the catalystic activity and selectivities of cobalt for CO[subscript 2] hydrogenation showed that the catalystic activity and selectivities to methane of cobalt supported MCM41 are 82.77 and 92.74% in reaction temperature at 270[subscript 2]. Furthermore, selectivities to methane of nickel supported on TiO[subscript 2]-SiO[subscript 2] microparticle composites are 100% in the CO[subscript 2] hydrogenation at 270℃. It has been found that nickel supported on TiSSP650 has the highest conversion about 82.77% in reaction temperature at 270℃.