A modification of bentonite with the Al-Fe mixed system in a concentrated medium was performed, assisting the intercalation with ultrasound. The solid pillaring agent and clay powder were placed in a dialysis membrane in contact with a minimum amount of water, and ultrasound was used to promote species exchange. Al-Fe pillared clays (2, 5 and 10 mol% Fe) were characterized by XRF, CEC, XRD, H-2-TPR and N-2 adsorption at 77 K, revealing changes in the structural and textural properties of the modified clays in the presence of ultrasound during the intercalation. The catalytic properties of pillared clays were evaluated by using the catalytic wet peroxide oxidation of phenol in a diluted aqueous medium, showing an activity comparable to that of a solid modified through the conventional method.