ABSTRACT
The TiO2 powder was prepared from the spent titanium chips by applying the sol-gel method with neutralization by NaOH solution. The prepared TiO2 powder was characterized using a particle size analysis, BET surface area, and XRD analysis. The crystal structure of the TiO2 powder was rutile type, and the powder was obtained to be nanosized. BET surface area of TiO2 powder was 118 m2/g, average particle size was 266.5 nm. The photocatalytic property of the TiO2 powder was evaluated as decomposition rate of methylene blue (MB) by using a liquid phase stirred reactor. Decomposition rate on TiO2 powder (P-25) was 1.5 times higher than that of the prepared TiO2 powder. Decomposition rate on the prepared TiO2 powder was linearly increased with increasing the amount of TiO2 powder, and approached to a specific value. MB concentration and decomposition rate was not correlated within the experimental range. The maximum value of decomposition rate at about pH 8 was 62%.
ABSTRACT
The greenhouse effect of carbon dioxide (CO2) has been recognized as one of the most serious problems in the world. Conversion of CO2 to methyl alcohol (CH3OH) was studied using catalytic chemical methods. Honeycomb-typed monolith used as catalyst support was 400 cell/inch2. Pretreatment of the monolith surface was carried out by thermal treatment and acid treatment. Monolith-supported nanosized CuO-ZnO catalysts were prepared by wash-coat method. The prepared catalysts were characterized by using SEM, TEM, and XRD. The catalytic activity for CO2 hydrogenation to CH3OH was investigated using a flow-type reactor with varying reaction temperature, reaction pressure and contact time. Conversion of CO2 was increased with increasing reaction temperature, but selectivity to CH3OH was decreased. Optimum reaction temperature was about 250 degrees C under 20 atm. Because of the reverse water gas shift reaction.
