Heterogeneous catalytic systems in the alkylation of phenols

Application data of different types of heterogeneous catalysts, such as zeolites, acid-treated metal oxides and heteropolyacids, in the alkylation of phenols are summarized. Heterogeneous catalysts have several advantages like recovering, recycling and dont demand additional steps to treating reaction mixture. Acidtreated metal oxides have proved to be available catalysts for alkylation. It is shown, that modifying of zeolite materials leads to increasing of selectivity of alkylation. Because of their structure and strong acidity heteropolyacides are the more selective catalysts than those discussed above.