Oxidation of styrene to benzaldehyde by p-toluenesulfonic acid using hydrogen peroxide in the presence of activated carbon

The selective oxidation of styrene to benzaldehyde catalyzed by p-toluenesulfonic acid (p-TsOH) in the presence of activated carbon (AC) was investigated with H2O2 as the oxidant. The reaction parameters of reaction time, temperature, catalyst mass, and styrene/H2O2 molar ratios were evaluated. A strong promoting effect of AC on the p-TsOH/H2O2 system was observed. The appropriate ratio and amounts of AC and p-TsOH were an important factor. The acidity of p-TsOH does not play a significant role. p-TsOH reacted with H2O2 by a non-radical process to oxidize styrene. The function of the AC was to activate H2O2 and to help the p-TsOH/H2O2 system in styrene oxidation. The reduction of oxygen containing groups (–OH, –COOH) on AC by a high temperature treatment or introduction of –SO3H groups onto AC affected the styrene conversion. The –SO3H groups were more effective than the oxygen-containing groups on the AC in promoting styrene oxidation.

In the p-toluenesulfonic acid/activated carbon/H2O2 system, there is an interaction of a radical reaction (HAC/H2O2) and non-radical process (p-TsOH/H2O2) for the oxidation of styrene to benzaldehyde.Figure optionsDownload as PowerPoint slide