Iron-alumina synergy in the heterogeneous Fenton-type peroxidation of phenol solutions

DI LUCA, CARLA; IVORRA, FERNANDO; MASSA, PAOLA; FENOGLIO, ROSA

CHEMICAL ENGINEERING JOURNAL

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2015 vol. 268 p. 280 - 289

1385-8947

Highly dispersed Fe2O3/Al2O3 catalysts (0.5?4 wt% Fe) were prepared by incipient wetness impregnation of iron citrate over a mesoporous alumina host. Their structural and textural properties were determined by N2 adsorption?desorption at 196 C, XRD, TEM, SEM?EDAX, Raman and XPS. The structure of the catalytic materials resulted similar to the c-Al2O3 support, exhibiting high dispersion levels of the iron oxide active phase with a narrow pore size distribution in the range of 2?7 nm and high surface areas. The capability of these systems as efficient and active Fenton-like catalysts, were further tested for the catalytic oxidation of concentrated phenol solutions (5 g/L) with H2O2 at 70 C in a batch reactor. The effects of iron concentration, catalyst concentration and the nature of the support were evaluated, under adjusted sub-stoichiometric oxidant concentration. Besides the positive impact of increasing the iron loading, a synergistic effect between Fe and Al species would be possibly responsible of the improvements observed using higher iron dispersions and/or support concentrations. The catalytic performance of these aluminabased catalysts resulted very promissory as they yielded: total phenol abatement, high mineralization levels (up to a maximum of 80%) and high oxidant consumption efficiencies (between 80% and 96%).