Application of the V-Mg-O/TiO2 catalyst on the selective oxidation of alcohols

Abstract

The application of V-Mg-O/TiO2 catalyst on the selective oxidation of methanol, ethanol, 1-propanol and 2-propanol was investigated. In this research, the various conditions have been performed to determine the suitable condition for each reaction. The amounts of oxygen and alcohol are varied in the range of 5-20 vol% and 4-12 vol%, respectively. The main products from ethanol and 1-propanol oxidation are acetaldehyde and propionaldehyde, respectively, and CO2. From investigating the effect of amounts of oxygen and alcohols, it is found that the CO2 selectivity has the lowest value at 5 vol% oxygen and the highest aldehyde yield obtained at 8 vol% alcohols. Thus, it can be concluded that one of the best alcohol/oxygen ratio is 8/5 which gives the best results. Then, the effect of GHSV is studied by changing from 60,000 to 20,000 ml/hr. g of catalyst or increasing the catalyst content from 0.1 to 0.3 g. The results show that an increase in the amount of catalyst or a decrease in the GHSV values gives the higher aldehydes yield. After that, the methanol oxidation is examined by using the methanol/oxygen ratio equals to 8/5. CO2 is the main product while CO is detected at high temperature. Due to CO formed, a further experiment is carried out by increasing the oxygen content to 20 vol%, the result shows that no CO is obtained. Therefore, it can be concluded that at 5 vol% oxygen used, the reaction is not complete combustion. For the oxidation of 2-propanol, propene and CO2 are the major product, which is different from the case of 1-propanol.