TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: Palladium precursor is acetic acid palladium, palladium nitrate, palladium chloride (acid) or palladium (hexafluoro) acetylacetonato.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: Preparing mesopore composite body involves forming thin gel film consisting of surface active agent and oxide source on the surface of porous support body, forming a multilayered structure and baking. Supporting palladium precursor in thin film involves impregnating palladium precursor solution in the mesopore of thin film in the composite body with basic functional group. Preferred Components: Oxide source is a silica e.g. colloidal silica, sodium silicate, tetralkyl ammonium silicate or silicon|silicone alkoxide. Surface active agent is cationic surfactant. Basic functional group is introduced at the terminal by using silane coupling agent with basic functional group preferably an amino group. Silane coupling agent with terminal basic functional group 3-aminopropyl triethoxysilane,N-methyl-3-aminopropyl triethoxysilane, N-(2-amino ethyl)-3-aminopropyl trimethoxysilane, N-(2-amino ethyl)-3-aminopropyl methyl-dimethoxysilane or (3-trimethoxysilylpropyl). EXAMPLE - Precursor solution for mesopore silica thin film was prepared by mixing tetra-ethoxy silane (TEOS), octadecyl trimethyl-ammonium bromide (CTAB), water, hydrochloric acid and ethanol at molar ratio of 1:10:50:0.25:38. The TEOS was hydrolyzed and the solution was used to dip-coat a porous alumina support body. Surface active agent was removed by baking at 500 degrees C for 24 hours and mesopore composite body (MS/Al2O3) with 300 nm thickness and dark blue color was obtained. The composite body was dried at 100 degrees C for 24 hours then placed bottom-faced in a 200 ml separable flask. A mixture of (ml) aminopropyl triethoxysilane (APS) (5) and dehydrated toluene (25) were added then heated at 110 degrees C under nitrogen at 20 ml/minute for 24 hours. The composite body was washed with dehydrated toluene (100) then dried at 60 degrees C for 24 hours to obtain mesopore silica thin film with amino group (APS/MS/Al2O3). The obtained thin film was dried in 100 degrees C for 24 hours then placed bottom-faced in 200 ml separable flask. Acidic palladium chloride aqueous solution (10 ml) was impregnated for 24 hours. The solution was removed by drying for 24 hours in vacuum to obtain a thin film with palladium. Palladium and APS/MS/Al2O3 were conjugated by sequential thermal processing in 20 ml/minute of oxygen, and 20 ml/minute of hydrogen at 300 degrees C to obtain mesopore composite body with palladium conjugated thin film (Pd/APS/MS/Al2O3).