Effects of pH on Ethanol Photocatalytic Oxidation Using TiO2 and Zeolite 13X as Catalyst

Photocatalytic oxidation is a very beneficial technique used in the treatment of various organic pollutants. In this research, two of the most prominent catalysts, TiO2 and zeolite 13X were tested for their ability in optimising the photocatalytic oxidation of ethanol in aqueous solution in terms of ethanol adsorption and production of acetaldehyde as an intermediate for the reaction. Besides that, the effects of pH on the photocatalytic oxidation of ethanol in an aqueous solution by using TiO2 and zeolite 13X as catalysts were also determined. The experiments were conducted under UV irradiation with the presence of dissolved oxygen. Samples were taken every 40 minutes for 200 minutes of irradiation at different pH values (pH 3, pH 5, pH 7 and pH 9) and then analysed by HPLC. The findings of the experiments indicated that TiO2 was a better catalyst compared to zeolite 13X in terms of ethanol adsorption (i.e. adsorbs more ethanol) and the production of acetaldehyde as an intermediate product (i.e. produces less acetaldehyde). The results also indicated that the optimum level for photocatalytic oxidation of ethanol was in acidic condition. It was also found that the duration of irradiation plays a big role and shows tremendous effect to the photocatalytic oxidation of ethanol.