In this work, three AlFePILCs prepared from different host clays were synthesized, characterized and tested in the catalytic wet hydrogen peroxide oxidation of 4-chlorophenol. Two reference clays, with widely different cation exchange capacities (1.2 meq/g for SAz-1 and 0.87 meq/g for SWy-2), and a Romanian montmorillonite (Mt) were used for the preparation of the catalysts, their structural and textural properties being determined by X-ray diffraction and nitrogen adsorption-desorption isotherms. The catalyst based on SAz-1 has a more ordered structure and a higher surface area than the other two catalysts, prepared from SWy-2 and Mt, and this was attributed to its higher layer charge. The 4-chlorophenol oxidation proceeds with the formation of 4-chlorocatechol (main reaction intermediate) and hydroquinone. Other chlorinated benzenediols and triols as well as dimerization products have been also identified by derivatization and GC-MS analysis. All the catalysts allowed the total elimination of 4-chlorophenol and significant removal efficiencies for the total organic carbon, of 60, 52 and 45%, for Mt. SWy-2 and SAz-1 based catalysts, respectively. The iron leaching was very low, but the most active catalyst produced the higher amount of dissolved iron (1 ppm), as compared with AlFePILCs based on SWy-2 and SAz-1 (0.5 ppm). To explain the differences in the catalytic properties, Mossbauer and diffuse-reflectance UV-vis spectroscopies were used to investigate the nature of the active sites. Both methods suggested the presence of two iron species: low-nuclearity ferric oxides and well-ordered hematite-like nanoparticles. The low-nuclearity ferric oxides seem to be responsible for the iron leaching and for the differences in the catalytic activity. (C) 2010 Elsevier B.V. All rights reserved.