Al,Cu-pillared clays as catalysts in environmental protection

In order to perform water purification from toluene Al,Cu-pillared clay (PILC) was synthesized and tested as catalyst in the oxidation of toluene. Two different catalytic reactions at moderate temperatures were investigated: catalytic wet peroxide oxidation (CWPO) using Al,Cu-PILC and electrooxidation in acidic solution using Al,Cu-PILC based electrode. X-ray diffraction analysis confirmed that pillaring was successful. Chemical analysis confirmed the incorporation of Al3+ and Cu2+ species in the PILCs. The Cu2+ species were proven to be the active ones in both reactions. CWPO in the presence of Cu containing PILC resulted in efficient catalytic degradation of toluene. Steady state voltammograms for Al,Cu-PILC based electrode in acidic toluene solution showed broad anodic peak at about 1.7V vs. Ag/AgCl ascribed to the electrooxidation of toluene. Another peak ascribed to toluene oxidation products occurred at 0.5V. Anodic peak currents corresponding to these peaks linearly increased with the initial toluene concentration. Both CWPO and electrooxidation confirmed the possibility of use of the synthesized Al,Cu-PILC in the toluene oxidation and might be employed in the environmental protection. (C) 2009 Elsevier B.V. All rights reserved.