Water as the solvent for the process of phenol hydroxylation over the Ti-MWW catalyst

Abstract

This work presents the studies on the process of phenol hydroxylation over the Ti-MWW catalyst. The medium of the reaction was water, whose amount was a sum of water introduced into the reactor with the 30 wt% hydrogen peroxide (oxidizing agent) and formed during the hydroxylation from the hydrogen peroxide (the first variant of the process) or water, which was the sum of water introduced additionally to the reaction mixture, water introduced with the oxidizing agent and formed during the reaction from the hydrogen peroxide (the second variant of the process). Studies have shown that in water solution, it is best to conduct phenol hydroxylation process at the temperature of 100 °C, phenol/hydrogen peroxide molar ratio 1, water content 62 wt%, catalyst content 8 wt% and during the reaction time of 180 min. Under these conditions, it is possible to achieve a selectivity of hydroquinone 43 mol%. A total conversion of phenol 28 mol%, and a selectivity of transformation to organic compounds in relation to phenol consumed 97 mol%.