EFFECT OF ION TYPES AND ION CONCENTRATIONS ON THE OXIDATION REACTION OF TOLUENE TO BENZALDEHYDE OVER AL-TS-1 CATALYST

Abstract

This research studies effects of ion types and ion concentrations on the oxidation reaction between toluene and hydrogen peroxide to benzaldehyde over titanium silicalite-1 catalyst modified with metallic aluminum (Al-TS-1). The catalyst is prepared by hydrothermal method and characterized by XRF, BET, FT-IR, and XRD techniques. The reaction is carried out at elevated temperatures in a pressurized autoclave reactor. It is found that increasing ion concentrations solution not only increases the concentration of toluene in an aqueous phase but also increases the reaction rate following the mechanism of a Langmuir-Hinshelwood. The amount of reactants on the catalyst surface must be appropriately controlled to achieve the highest reaction rate. If most of the catalyst surface is covered by one reactant, this will lead to decreasing of product. Therefore, ion concentrations have affected reaction rate. Moreover, we attempt to increase the consumption of hydrogen peroxide by increasing reaction time and decreasing amount of hydrogen peroxide. The results show that the amount of hydrogen peroxide converted to benzaldehyde is about the same or slightly increase. It may have the significant factors that affect the reaction; hence, hydrogen peroxide does not complete consumption.