Di-, tri- and tetra-valent ion-exchanged NaY zeolite: Active heterogeneous catalysts for hydroxylation of benzene and phenol Original Research Article

Ion-exchanged NaY zeolite with various valent cations are tested for hydroxylation of benzene and phenol with H2O2 in 1:1 and 3:1 molar ratios, respectively; the highest conversion of benzene (33%) in green one-step process is achieved using Cu–NaY with 100% selectivity to phenol, while OV–NaY shows >36% phenol conversion with 91% selectivity to catechol, whereas TOF exceeds 1000 with Zn–NaY after 6 h reaction time which is among the highest value reported so far.