Hydroxylation of phenol by hydrogen peroxide catalyzed by heteropoly compounds in presence of glycerol as green solvent

•Glycerol was applied, for the first time, as green solvent in phenol oxidation.•Influence of metal cations on selectivity of products in phenol oxidation has been explained.•Iron salts of tungstophosphoric acid are active catalysts in oxidation of phenol to catechol and hydroquinone.•Manganese and cobalt heteropoly salts are efficient catalysts in degradation of phenol to CO2.