Catalytic Performance of Magnesium Ferrite for Hydroxylation of Phenol with Hydrogen Peroxide

A novel catalyst, MgFe 2O 4, for hydroxylation of phenol with hydrogen peroxide was synthesized via coprecipitation method from an aqueous solution containing Fe(NO 3) 3·9H 2O and Mg(NO 3) 2·6H 2O with ammonia. The X ray diffraction peaks of the catalyst show that the as prepared sample has engendered MgFe 2O 4 crystal with spinel structure, which is also confirmed by its IR spectrum. In the hydroxylation of phenol with hydrogen peroxide, MgFe 2O 4 catalyst exhibited high activity after a short induction period. In particular, the addition of a little amount of acetic acid in the reaction liquid can effectively shorten the induction period. Under the same reaction conditions, the diphenol selectivity over MgFe 2O 4 is higher than that over TS 1, furthermore, the reaction time is shortened greatly. The experimental phenomena can be explained by the free radical mechanism.