Oxidation of hydroquinones to benzoquinones with hydrogen peroxide using catalytic amount of silver oxide under batch and continuous-flow conditions

Article abstract of DOI:10.1016/j.jcat.2010.02.015

Silver oxide (Ag₂O) can be utilized as heterogeneous catalyst in the oxidation of hydroquinones to the corresponding benzoquinones with 30% aq. H₂O₂. The catalytic properties of Ag₂O have been explored in the model reaction of methylhydroquinone with H₂O₂ performed under batch conditions. Results show that the reaction can be carried out in high yield and selectivity at room temperature under environmentally friendly conditions. The truly heterogeneous catalyst can be recovered by filtration and reused for at least five times, giving the same excellent results (～95% yield, ～98% selectivity). The catalyst can be packed in a tubular reactor and utilized under continuous-flow conditions giving similar good results.