• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.723-728
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• 2012

The production of biodiesel by transesterification of soybean oil was performed on $MoO_3$, $SnO_2$ and $CeO_2$ mixed oxides. The catalysts were characterized using XRD and $NH_3$-TPD. $MoO_3$ showed the highest activity among the three metal oxides. When 7 wt% of catalysts was introduced into the reactants, the highest activity was obtained and the water added to reactant decreased the catalytic activity. $MoO_3$ and $SnO_2$ mixed with 50:50 showed the highest activity and $CeO_2$ added with 20% on the $MoO_3-SnO_2$ mixed oxide also showed the highest activity. The catalytic activity showed to have a good relationship with the amount of acid site of catalysts. When the waste soybean oil was used as a reactant, the conversion was decreased about 30%.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.651-656
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• 2005

Toluene, which is emitted from textile process, is considered as an important hazardous air pollutant. In this study, the catalytic activity of transition metal oxides(Cu, Mn, V, Cr, Co, Ni, Ce, Sn, Fe, Sr, Cs, Mo, La, W, Zn)/${\gamma}-Al_2O_3$ catalysts was investigated to carry out the complete oxidation of toluene. The metal catalysts were characterized by XRD-ray diffraction), FE-SEM(Field Emission Scanning Electron Micrograph), BET(Brunauer Emmett Teller) method and TPR(Temperature Programmed Reduction). Among the catalysts, Cu/${\gamma}-Al_2O_3$ was highly promising catalyst for the oxidation of toluene. From the BET results, it seems that the catalytic activity is not correlated to the specific surface area. XRD results indicated that most of catalysts exist as amorphous phase. From the FE-SEM results, it was observed that copper on ${\gamma}-Al_2O_3$ surface was well dispersed among catalysts. The catalytic activity for the toluene oxidation could be explained with that metal oxide catalyst was dispersed well over supports and was attributed to reduction activity in surface of catalysts.