Selective hydroxylation of benzene to phenol via C[sbnd]H activation over mesoporous Fe2O3-TiO2 using H2O2.

• Remarkable characteristics of mesoporous Fe 2 O 3 -TiO 2 mixed oxides were studied. • Fe-loading influenced the acidic property of the catalyst. • The acidic property of the catalyst plays a predominant role in the selective hydroxylation of benzene. The omnipresence of C H bonds in organic molecules enamors chemists for the functionalization of C H bonds towards value-added molecular scaffolds. Mesoporous Fe 2 O 3 -TiO 2 mix-oxide catalyst has been successfully synthesized via a triblock-copolymer (P123) mediated sol-gel method and catalytically tested in selective hydroxylation of benzene. The as-synthesized catalysts were comprehensively characterized by powder XRD, Raman spectroscopy, FT-IR, N 2 -physisorption, FESEM, HRTEM, XPS, and NH 3 -TPD techniques. The physicochemical characterizations evidence that Fe(III) ions incorporate into the pure anatase TiO 2 lattice framework and the crystallite size decreases as iron concentration increases. The XPS analyses confirm the Fe3+ state (BE 710.3 eV) in Fe-O-Ti with a peak at 712.1 eV for Fe3+ of Fe 2 O 3. The NH 3 -TPD results show that the 5 wt% Fe-TiO 2 has a higher total acidity of 105 µmol/g. Interestingly, a further increase in iron amount decreases the total acidity. Herein, we observe that the surface acidity directs the selectivity towards phenol. The effect of different reaction parameters was carefully investigated. Under the optimized conditions, 5% Fe-TiO 2 with notified strong acid sites gives a higher phenol yield of 31.2% with > 99% selectivity; moreover, the catalyst is reusable at least four times. C H activation of benzene over mesoporous Fe 2 O 3 -TiO 2 mixed oxide synthesized by conventional sol-gel method [Display omitted] [ABSTRACT FROM AUTHOR]