Production of cresols in a one-step reaction

Abstract

This research is a study on the synthesis of cresol in a one-step reaction from toluene and hydrogen peroxide using titanium silicalite-1 (TS-1) catalysts modified with different amount of Co. The reaction is carried out at reaction temperature 70 C and 90 C, and toluene per hydrogen peroxide molar ratios 1:1 and 2:1. The research found that the addition of Co up to 0.124 mol% does not the structure of TS-1. Catalytic activity testing found that all modified catalysts yield o-cresol and p-cresol as the major products with benzaldehyde as by products. Selectivity toward cresols increases with the increase in reaction temperature. On the contrary, benzaldehyde selectivity decreases if toluene per hydrogen peroxide molar ratio is increased from 1:1 to 2:1. This is due to toluene will cover the catalyst surface, leaving lesser hydrogen peroxide on the catalyst surface. The formation of benzaldehyde which requires twice amount of hydrogen peroxide than the formation of cresol, therefore, decreases. The formation of cresols which requires lower hydrogen peroxide concentration on the catalyst surface, therefore, increases. The experimental results also show that the addition of Co into TS-1 suppresses the formation of benzaldehyde and increases the selectivity toward cresols. Too much Co added, however, will decrease the catalytic activity of the modified catalysts.