Tailoring the stability and photo-Fenton activity of Fe-modified nanostructured silicates by tuning the metal speciation from different synthesis conditions?. Molecular Catalysis

ELIAS V; PABLO A. OCHOA; E VASCHETTO; GINA PECCHI; CRISTIÁN HUCK-IRIART; CASUSCELLI S; EIMER G

Molecular catalysis

Elsevier B.V

Año: 2018 vol. 481 p. 110217 - 110230

2468-8231

The stability and photo Fenton activity of nanoarchitectured silicates modified with Fe by the wet impregnationmethod were studied as a function of the used solvent, calcination temperature and iron loading. The physicochemical properties were characterized by SAXS, XRD, N2 physisorption, SEM, AA, UV?Vis DR, XPS and TPR.All solids showed long-range structural order typical of SBA-15 with high specific surface, PV and a narrowdistribution of PD. The proper choice of impregnation solvent allowed tuning the iron speciation in order toobtain catalysts highly stable and efficient for their use in the azo dyes photo-Fenton degradation at pH = 3.5.Calcination temperature does not seem influence on such speciation. Isolated iron cations finely dispersed andstrongly anchored on the mesoporous channels, whose formation is promoted by the use of ethanol and the lowiron loading, are proposed as active sites for the photo-Fenton process. Likewise, low iron loadings also favor thehigher accessibility of these sites to the reactant molecules (AO7 and H2O2). Thus, the highest dye mineralizationdegree was obtained by an actual iron loading of 1.31% wt. The heterogeneity of the process was confirmed. Themore active solid also showed a high stability and reuse capacity, maintaining its performance.