Synthesis, characterization and kinetic application of activated with palladium sba-15 type catalysts

In this work, SBA-15 supported PdO catalysts were synthesized by two different methods, namely, Direct Hydrothermal Synthesis (DHS) and wet impregnation (IMP) and characterized by the N2 Adsorption/Desorption, XRD, SEM, CO Chemisorption and TPR analysis. According to the analysis results, it was proved that all samples had the characteristic structure of SBA-15 type catalysts. It was seen that PdO crystals were formed on the outside surfaces of the DHS catalysts under strongly acidic conditions, palladium oxide particle were mostly dispersed in the pores of the IMP catalysts and embedded in their amorphous silica walls and structure deterioration was more pronounced for the IMP samples than the DHS sample at high palladium loadings. The DHS samples were found to have higher BET surface areas (>763.2 m2/g) and higher pore volumes (>0.97 cm3/g) compared to the IMP samples (>626.0 m2/g, >0.93 cm3/g). The activities of the catalysts were tested in the gas phase oxidative production of ethyl acetate. The optimum conversion and ethyl acetate yield values were obtained with the %3PdO-SBA-15-IMP catalyst as 0.680 and %24.8 at a while O2/ethanol molar ratio of 0.5 and a reaction temperature of 250 ?C.